Answer:
225 u²
Explanation:
The area of the larger square is 625 u². We know that area of square is the square of side. So ,
⇒ a² = 625 u²
⇒ a = √625 u²
⇒ a = 25 u .
Similarly finding the side of second square as ,
⇒ a'² = 400 u²
⇒ a' = √400 u²
⇒ a' = 20 u
If we see these are the hypontenuse and base of a right a Angled triangle formed between the square. The measure of perpendicular will be the side lenght of third square.
⇒ h² = p² + b²
⇒( 25u)² = p² + (20u)²
⇒ p² = 625 - 400 u²
⇒ p² = 225 u²
This p² is only the area of square .
Hence the area of third square is 225 u² with a side lenght of 15 u .