Answer:
Step-by-step explanation:
The diagonal forms two 45-45-90 triangles, with the diagonal being the hypotenuse of both. The Pythagorean Theorem states that 
, where 
is the hypotenuse of the triangle, and 
and 
are the two legs of the triangle.
From the Isosceles Base Theorem, the two legs of a 45-45-90 triangle are always equal. Since we're given a diagonal of 
, we have:
So, you should add the heighth twice and add the width twice too, then add those two together to get your answer.
The answer is the first one A. sss Postulate
The answer is 5 you can also use your fingers no I’m not calling you dumb I’m just saying you can
