A right triangle has sides A, B, and C. Side A is the hypotenuse and side B is also a side of a rectangle. Sides A, C, and the side of the rectangle adjacent to side B have lengths of #13 #, #9 #, and #3 #, respectively. What is the rectangle's area?
As is my practice, I'm converting to standard notation where triangle sides are small letters
A right triangle has hypotenuse
The area we seek is