Final: Master of Triangles

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

A roof truss is an isosceles triangle. Its two sloping beams are 13 m each, and the horizontal beam along the bottom is 24 m. An upright post runs from the peak down to the middle of the bottom beam, meeting it at a right angle.

Find the area of the triangle and the total length of its three outer beams.

Challenge

The truss △ABC has AB = AC = 13 and BC = 24, with the post AD to the midpoint D. Find both its area and its perimeter, then press Check.

Try it yourself

$Find the marked part of the figure$

Find the marked part of the figure

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

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

3Perimeter

Around the Edge A Missing Side Isosceles Perimeter Sides as Expressions Recap: Around the Edge

6Finding a Leg

Working Backwards The Ladder Which Side Is c?A Leg That Is Not Whole Recap: Finding a Leg

9Similar Triangles

Same Shape, Different Size The Scale Factor Finding a Side Matching the Corners Recap: Similar Triangles

12Final Challenges

Final: Three Sticks Final: The Fence Final: The Ladder Final: The ShadowFinal: Master of Triangles