The Miscellaneous Triangles ClipArt gallery includes illustrations of isosceles, scalene, equilateral, obtuse, acute, concentric, and similar triangles. There are also images of real-world triangles that can be used in application problems, triangles with bisectors drawn, and triangles that are labeled to derive the area formula.

Illustration to show that the bisector of the vertical angle of an isosceles triangle bisects the base, and is perpendicular to the base.

Bisected Vertical Angle of an Isosceles Triangle

Illustration to show that the bisector of the vertical angle of an isosceles triangle bisects the base,…

"The triangle ABC is divided into 2 right triangles I and II. ABC is seen to be equal to 1/2 of the rectangle ABNO." -Foster, 1921

Area of Triangle

"The triangle ABC is divided into 2 right triangles I and II. ABC is seen to be equal to 1/2 of the…

"The child sees triangle ACB = triangle ADB, and that I + II = CA - DB; and so he sees that the area of triangle=1/2 area of rectangle whose base and altitude are the same as those of the triangles." -Foster, 1921

Area of Triangle

"The child sees triangle ACB = triangle ADB, and that I + II = CA - DB; and so he sees that the area…

"Fig. 3 shows triangle I = triangle II, III = IV, and so triangle ABC = 1/2 of rectangle ABDE. The fact is realized that the area of a triangle equals 1/2 the product of the base and altitude." -Foster, 1921

Area of Triangle

"Fig. 3 shows triangle I = triangle II, III = IV, and so triangle ABC = 1/2 of rectangle ABDE. The fact…

An equilateral triangle is one having all of its sides equal.

Equilateral

An equilateral triangle is one having all of its sides equal.

Illustration of an equilateral triangle that shows both the centroid (where the medians of the sides meet) and the incenter (where the angle bisectors meet).

Centers of Equilateral Triangle

Illustration of an equilateral triangle that shows both the centroid (where the medians of the sides…

Illustration of 10 congruent equilateral triangles that have the same center. Each triangle has been rotated 12° in relation to the one next to it.

10 Congruent Rotated Equilateral Triangles

Illustration of 10 congruent equilateral triangles that have the same center. Each triangle has been…

Illustration of 2 concentric equilateral triangles.

2 Concentric Equilateral Triangles

Illustration of 2 concentric equilateral triangles.

Illustration of 2 concentric equilateral triangles.

2 Concentric Equilateral Triangles

Illustration of 2 concentric equilateral triangles.

Illustration of 20 congruent equilateral triangles that have the same center. Each triangle has been rotated 6° in relation to the one next to it.

20 Congruent Rotated Equilateral Triangles

Illustration of 20 congruent equilateral triangles that have the same center. Each triangle has been…

Illustration of 3 concentric equilateral triangles that are equally spaced.

3 Concentric Equilateral Triangles

Illustration of 3 concentric equilateral triangles that are equally spaced.

Illustration of 4 concentric equilateral triangles that are equally spaced.

4 Concentric Equilateral Triangles

Illustration of 4 concentric equilateral triangles that are equally spaced.

Illustration of 5 congruent equilateral triangles that have the same center. Each triangle has been rotated 24° in relation to the one next to it.

5 Congruent Rotated Equilateral Triangles

Illustration of 5 congruent equilateral triangles that have the same center. Each triangle has been…

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a right triangle .

Ladder Leaning Against a Tree

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a…

Illustration that uses triangles to measure the distance across a lake.

Using Triangles To Measure A Lake

Illustration that uses triangles to measure the distance across a lake.

Illustration that uses triangles to measure the distance across a lake.

Using Triangles To Measure A Lake

Illustration that uses triangles to measure the distance across a lake.

Triangle with medians drawn.

Triangle with Medians

Triangle with medians drawn.

Pentagon with dimensions labeled. Pentagon can be used to calculate area by calculating individual triangles and finding the sum of the areas.

Pentagon With Triangular Sections For Area

Pentagon with dimensions labeled. Pentagon can be used to calculate area by calculating individual triangles…

Polygon consisting of 3 sides

3-sided Polygon

Polygon consisting of 3 sides

Triangle, triangular polygon

Triangular Polygon

Triangle, triangular polygon

Illustration that uses triangles to measure the distance across a river.

Using Triangles To Measure A River

Illustration that uses triangles to measure the distance across a river.

Illustration that uses triangles to measure the distance across a river.

Using Triangles To Measure A River

Illustration that uses triangles to measure the distance across a river.

Illustration that uses triangles to measure the distance across a river.

Using Triangles To Measure A River

Illustration that uses triangles to measure the distance across a river.

A scalene triangle is one having no two of its sides equal.

Scalene

A scalene triangle is one having no two of its sides equal.

An illustration of a square and triangles within the square. This is an example of a problem that can be used to fine the distances of two inaccessible objects without measuring elevation and whether on a horizontal plane or not.

Square

An illustration of a square and triangles within the square. This is an example of a problem that can…

Illustration of a giant stepladder, sometimes called a skyscraper stepladder, that is opened next to a palm tree. One of the bottom legs of the unfolded ladder is adjacent to the tree. The ladder forms an isosceles triangle with the ground.

Skyscraper Giant Stepladder

Illustration of a giant stepladder, sometimes called a skyscraper stepladder, that is opened next to…

Triangle with sides a, b, c and angles A, B, C labeled.

Triangle

Triangle with sides a, b, c and angles A, B, C labeled.

Triangle with sides labeled with numerals 28, 36, 40 and angles A, B, C labeled.

Triangle 28, 36, 40

Triangle with sides labeled with numerals 28, 36, 40 and angles A, B, C labeled.

Triangle with labels A, B, C, D

Triangle

Triangle with labels A, B, C, D

Triangle with segments drawn.

Triangle With Segments

Triangle with segments drawn.

Triangle with height/altitude h and median m.

Triangle With Height and Median

Triangle with height/altitude h and median m.

An illustration of a triangle comprised of a church and two lines. This illustration can be used to determine the height of the church steeple, the hypotenuse, and distance of the tower from object one and two.

Triangle with Church

An illustration of a triangle comprised of a church and two lines. This illustration can be used to…

An illustration of a three triangles created with boats and a lighthouse. This is an example illustration used to fine the height of an object situated about the plane of observation, and its height above the plane.

Triangle with Lighthouse

An illustration of a three triangles created with boats and a lighthouse. This is an example illustration…

An illustration of a triangle comprised of a tower and two lines. This illustration can be used to determine the height of the tower, the hypotenuse, and distance of the tower from the object.

Triangle with Tower

An illustration of a triangle comprised of a tower and two lines. This illustration can be used to determine…

An illustration of a triangle comprised of a tree and two lines. This is an example of a problem that can be used to fine the distance of an inaccessible object without measuring elevation and whether on a horizontal plane or not.

Triangle with Tree

An illustration of a triangle comprised of a tree and two lines. This is an example of a problem that…

37-49-94 Triangle

Triangle 37-49-94

37-49-94 Triangle

Illustration showing a triangle with angles A, B, and C labeled.

Triangle ABC

Illustration showing a triangle with angles A, B, and C labeled.

Illustration showing an acute triangle (one that has all three angles that are acute).

Acute Triangle

Illustration showing an acute triangle (one that has all three angles that are acute).

An illustration of an acute triangle with the height/altitude labeled h.

Acute Triangle

An illustration of an acute triangle with the height/altitude labeled h.

Illustration showing a triangle with an altitude CD passing through the middle of EF. Triangles AEC and BFC are isosceles.

Triangle With Altitude and Isosceles Triangles Within

Illustration showing a triangle with an altitude CD passing through the middle of EF. Triangles AEC…

Illustration to show altitudes drawn from base angles of an isosceles triangle.

Altitudes Drawn from Base Angles of Isosceles Triangles

Illustration to show altitudes drawn from base angles of an isosceles triangle.

Illustration showing the three angle bisectors in a triangle.

Angle Bisectors In A Triangle

Illustration showing the three angle bisectors in a triangle.

Parallelogram illustration to show where the area of a triangle formula comes from.

Area of Triangle

Parallelogram illustration to show where the area of a triangle formula comes from.

Illustration of triangle ABC with altitude a and base b to be used to demonstrate that the area is 1/2ba.

Area of a Triangle

Illustration of triangle ABC with altitude a and base b to be used to demonstrate that the area is 1/2ba.

Illustration to show the bisector of the vertical angle of a triangle makes with the perpendicular from the vertex to the base an angle equal to half the difference of the base angles.

Triangle With Bisector and Perpendicular From Vertex Drawn

Illustration to show the bisector of the vertical angle of a triangle makes with the perpendicular from…

Illustration to show that the bisector of an exterior angle of an isosceles triangle, formed by producing one of the legs through the vertex, is parallel o the base.

Bisector of an Exterior Angle of an Isosceles Triangle

Illustration to show that the bisector of an exterior angle of an isosceles triangle, formed by producing…

Illustration of a triangle showing that when a line parallel to the base of a triangle bisects one side, it bisects the other side also.

Triangle With Bisector Parallel to the Base

Illustration of a triangle showing that when a line parallel to the base of a triangle bisects one side,…

Illustration to show if the bisector of the base angles of a triangle are drawn, and through their point of intersection a line is drawn parallel to the base, the length of this parallel between the sides is equal to the sum of the segments of the sides between the parallel and the base.

Triangle With Bisectors of Base Angles

Illustration to show if the bisector of the base angles of a triangle are drawn, and through their point…

Illustration to show the bisector of the vertical angle A of a triangle ABC, and the bisectors of the exterior angles at the base formed by producing the sides AB and AC, meet in a point which is equidistant from the base and the sides produced.

Triangle With Bisectors of Vertical Angles

Illustration to show the bisector of the vertical angle A of a triangle ABC, and the bisectors of the…

Illustration to show medians in a triangle. It is known as the centroid.

Centroid of Triangle

Illustration to show medians in a triangle. It is known as the centroid.

Illustration to show perpendicular bisectors in a triangle. It is known as the circumcenter.

Circumcenter of Triangle

Illustration to show perpendicular bisectors in a triangle. It is known as the circumcenter.

Triangle construction when given two angles and the included side.

Triangle Construction When Given 2 Angles and Included Side

Triangle construction when given two angles and the included side.

Triangle with dimensions labeled. Triangle can be used to calculate area.

Triangle With Dimensions

Triangle with dimensions labeled. Triangle can be used to calculate area.

Triangle with dimensions labeled. Triangle can be used to calculate area.

Triangle With Dimensions

Triangle with dimensions labeled. Triangle can be used to calculate area.

Illustration showing an equiangular triangle (one that has all three angles that are equal).

Equiangular Triangle

Illustration showing an equiangular triangle (one that has all three angles that are equal).

"Having equal sides." — Williams, 1889

Equilateral triangle

"Having equal sides." — Williams, 1889

Sketch of equilateral triangle with bisectors, medians, and altitudes.

Equilateral Triangle

Sketch of equilateral triangle with bisectors, medians, and altitudes.

Illustration showing an equilateral triangle (one that has three sides equal).

Equilateral Triangle

Illustration showing an equilateral triangle (one that has three sides equal).

An illustration showing a triangle with interior angles A, B, C, and exterior angles D, and A' + B'.

Exterior And Interior Angles Of A Triangle

An illustration showing a triangle with interior angles A, B, C, and exterior angles D, and A' + B'.

Illustration showing a triangle with exterior angles. This can be used to show the sum of the three angles of a triangle is equal to two right angles.

Triangle with Exterior Angles Drawn

Illustration showing a triangle with exterior angles. This can be used to show the sum of the three…