Answer:
A = 25 units²
Explanation:
You need to visualize two triangles on the lower left and right that are OUTSIDE of the square.
One leg of the first triangle is formed by starting at Point A and going down 4 units. The other leg is formed by starting at point D and moving left 3 units. Line segment AD is the hypotenuse of this triangle.
The leg lengths are 3 and 4, so the hypotenuse is...
3² + 4² = c²
9 + 16 = c²
25 = c²
5 = c
So side AD of the square is 5 units long.
We can do the same concept using points C and D. We can make a triangle that has legs with length 3 and 4 with CD being the hypotenuse. The length of CD is therefore 5 as well.
The area of the square is
A = 5*5 = 25 units²