CPM Homework Help : CCG Problem 10-56

A triangle, with its obtuse angle on the bottom right, sides labeled as follows: bottom, 9 inches, left, 20 inches. A dashed line segment, from bottom right vertex, perpendicular to the left side, labeled, h. A dashed line segment extends the bottom side to the right. A dashed line segment from the top right vertex, perpendicular to the extended dashed side, is labeled, 12 inches. In the figure at right, find the interior height ( $h$ ) of the obtuse triangle. Show all work.

Hint:

$9$ and $12$ are the base and height, but so are $20$ and $h$ . How can you use this fact?