Recap: Special Triangles

Part of the Triangles section of Coddy's Geometry journey. Lesson 43 of 63.

Challenge

△ABC has a right angle at B, and its side BC is extended past C to E. The exterior angle at C is 135°. Find the exact length of AC, then press Check.

Try it yourself

$Find the marked part of the figure$

Find the marked part of the figure

All lessons in Triangles

2The Triangle Inequality

Can Three Sticks Meet?Exactly Reaching The Range of the Third Side The Formula Recap: The Third Side

5The Pythagorean Theorem

Squares on the Sides Finding the Hypotenuse Pythagorean Triples When It Is Not Whole Recap: The Hypotenuse

8Special Right Triangles

The 45-45-90 Triangle Legs from the Hypotenuse The 30-60-90 Triangle All Three Sides Which Triangle Is It?Recap: Special Triangles

11Two Tools at Once

Height of an Isosceles Area from the Height The Equilateral Triangle Right Triangle Perimeter Recap: Two Tools