# 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 , 4 , and 5 , respectively. What is the rectangle's area?

Area of rectangle is $61.85$ sq. units.
As in the right angled triangle, $A$ is hypotenuse of length $13$ and $C$ is $4$, side $B = \sqrt{{13}^{2} - {4}^{2}} = \sqrt{169 - 16} = \sqrt{153} = 12.37$
As the other side of rectangle at side $B$ is $5$, area of rectangle is $12.37 \times 5 = 61.85$