Answer:
C. 503.6
Explanation:
The shape is a square and the missing value is the area of the square.
Because it is a square the value of one side is the same for all sides.
The value for the side bordering the triangle is 22.44 so all other sides are 22.44 as well.
22.44 * 22.44 = 503.55 which rounded to the nearest tenth is 503.6.