Answer:

Explanation:
we know that
The total area of the figure is equal to the area of the square plus the area of the triangle
step 1
Find the area of triangle
The area of triangle is equal to

where
b is the base of triangle (is the same that the length side of the square)
h is the height of triangle
we have

Applying the Pythagorean Theorem
Find the length side b




Area of triangle

step 2
Find the area of the square
The area of the square is

we have

substitute

step 3
Find the total area of the figure
Adds the areas
