Illustration of two straight lines, m and n, cut by a transversal t.

2 Lines Cut By A Transversal

Illustration of two straight lines, m and n, cut by a transversal t.

Illustration of two straight lines, AB and CD, cut by a transversal EF.

2 Lines Cut By A Transversal

Illustration of two straight lines, AB and CD, cut by a transversal EF.

Illustration used to prove the theorem "The line bisecting one of the non parallel sides of a trapezoid and parallel to the bases bisects the other of the non parallel sides also."

Line Bisecting Trapezoid Sides

Illustration used to prove the theorem "The line bisecting one of the non parallel sides of a trapezoid…

Triangle with segments drawn.

Triangle With Segments

Triangle with segments drawn.

Illustration used to show "The altitudes of a triangle are concurrent."

Altitudes In A Triangle

Illustration used to show "The altitudes of a triangle are concurrent."

Illustration used to prove "The bisectors of the angles of a triangle are concurrent in a point which is equidistant from the three sides of the triangle."

Angle Bisectors In A Triangle

Illustration used to prove "The bisectors of the angles of a triangle are concurrent in a point which…

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 lines drawn from the vertices to join at a point within the triangle.

Triangle With Lines From the Vertices That Join a Point Within

Illustration to show lines drawn from the vertices to join at a point within the triangle.

Illustration used to show "Any two medians of a triangle intersect each other in a trisection point of each."

Medians In A Triangle

Illustration used to show "Any two medians of a triangle intersect each other in a trisection point…

Illustration used to prove "The perpendicular bisectors of the sides of a triangle are concurrent in a point which is equidistant from the three vertices of the triangle."

Perpendicular Bisectors In A Triangle

Illustration used to prove "The perpendicular bisectors of the sides of a triangle are concurrent in…

Illustration showing an angle of 23 degrees 40 minutes making a triangle in a city block and marking off streets at 100 foot intervals.

Triangular City Block With Angles and Lengths

Illustration showing an angle of 23 degrees 40 minutes making a triangle in a city block and marking…

OP is a line representing a vector (directed quantity)

Vector

OP is a line representing a vector (directed quantity)

OP is a vector (directed quantity) showing the force by a weight acting on it at an angle of 20 degrees.

Vector Showing Force at Angle of 20 degrees

OP is a vector (directed quantity) showing the force by a weight acting on it at an angle of 20 degrees.

A vertical line with arrows at both ends to show that it extends indefinitely.

Line, Vertical

A vertical line with arrows at both ends to show that it extends indefinitely.

A vertical line with arrows at both ends to show that it extends indefinitely.

Line, Vertical

A vertical line with arrows at both ends to show that it extends indefinitely.

Vertical lines are drawn by using a triangle held against the T-square.

Drawing a Vertical Line

Vertical lines are drawn by using a triangle held against the T-square.

Vertical line is drawn downward with the pencil held with freedom, not close to the point.

Sketching Vertical Line

Vertical line is drawn downward with the pencil held with freedom, not close to the point.