Answer:
58 units squared
Explanation:
**I'm doing the question with the 7 by 3 triangle in the picture, not 777 by 333**
Pythagorean Theorem:
, where c is the length of the hypotenuse.
The given sides are legs, therefore,
c is also one of the sides of the square. A square's area is one of the sides' lengths squared, so: