Anyone that can explain this question to me and answer?

Explaining the Concept:

To get the perimeter of this square, we will first get the value of one side

Since all the sides of a square are equal, we will find the length of one of the side from the triangle EOF

Finding the length of one side of the triangle:

In triangle EOF:

Using the pythagoras's theorem

EO²+OF² = EF²

(5)² + (5)²=  side²       [since EF is a side of the square]

side²=  50

side = √50

side = 5√2 units

Perimeter of the Square:

We know that the perimeter of a square is 4 times its side

Perimeter  = 4 * side

Perimeter = 4 * 5√2

Perimeter = 20√2 units