Which of the following is a perfect square?
A. 400
B. 210
C. 37
D. 199

A 400

Step-by-step explanation:

400 is a perfect square because its square root is 20, 20 is an integer so it is 400. I’m not entirely sure how to explain it but i know I’m correct.

step-by-step explanation:

use pothagarean therom

a^2+b^2=c^2 so first ac

acm is a right triangle because c= 90°

and am (the hypotenuse or c) =16+9 =25

but there is not enough info we need another angle or side length