Illustration to show the perpendiculars dropped from any point in the equilateral triangle to the three…

Illustration to show the perpendiculars dropped from the midpoint of the base to the legs of an isosceles…

Illustration to show that the difference of the distances from any point in the base produced of an…

Trigonometric reference triangles/angles drawn for 60 degree reference angel in quadrants I and II.

Inclined plane forming right triangle showing the velocity of a body sliding a distance,s, down a smooth…

Right triangle OQP with angle of 35 degrees, height of .70 inches, and leg of 1 inch.

Right triangle OQP with angle of 40 degrees, height of .64 inches, and hypotenuse of 1 inch.

Right triangle ABC with a base angle of 67 degrees 4208 minutes and a hypotenuse of 23.47 ft.

Right triangle ABC with a leg of 23.85 feet and a hypotenuse of 35.62 feet.

Illustration of a right triangle with one angle the double of the other.

Illustration showing a triangle with an exterior segment drawn to show and exterior angle. This can…

Special right triangle with angles 30 degrees, 60 degrees, and 90 degrees with side measures/relationships…

Special right triangle with angles 45 degrees, 45 degrees, and 90 degrees with side measures/relationships…

Illustration showing two equal triangles. This can be used to show that two triangles are equal if the…

Illustration to show if two triangles have two sides of the one equal, respectively, to two sides of…

Trigonometric reference triangles/angles drawn for reference angel in quadrants I and II. This illustration…

Illustration showing two equal right triangles. This can be used to show that two right triangles are…

Illustration showing three triangles. This is used to show the following theorem: If two triangles have…

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

"In trigonometry, the arcs of circles are used to measure angles. All angles are supposed to have their…

Right triangle OCA, inside of Circle O is used to show that side AC is "opposite" O and side OC is "adjacent"…

"Direction of the needle when placed at a right angle to the uniting wire." -Comstock 1850

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

"Suppose the object a, appears to the naked eye of the length repreesnted in the drawing. Now, as the…

"1, Screw-wrench; 2, Tap-wrench; 3, Angle-wrench; 4, Tube-wrench; 5, Monkey-wrench for hexagonal and…