Finding the Height

Part of the Triangles section of Coddy's Geometry journey. Lesson 20 of 63.

If you know the area and the base, the formula gives the height. Put the numbers into A = 1/2 × b × h and solve for h.

$Triangle with base 12, height h and area 48$

Here 48 = 1/2 × 12 × h. Half of 12 is 6, so 48 = 6h and h = 8. Check: 1/2 × 12 × 8 = 48.

On the board, tap the height or the base, pick Area of a triangle, and the board writes this equation from the labels for you. Then solve it.

Challenge

△ABC has area 55 and base 10. Tap a part, pick the rule, and solve the equation the board writes for the height h.

Then press Check.

Try it yourself

$Use the figure to find h$

Use the figure to find h

Test yourself

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

All lessons in Triangles

1Sides and Names

4Area of a Triangle

7Is It Right?

10Scale in the World

2The Triangle Inequality

5The Pythagorean Theorem

8Special Right Triangles

11Two Tools at Once