Answer:
The correct answer is option a. 400
Step-by-step explanation:
Points to remember
Area of square = a²
Where 'a' is the side length of square
To find the area of square
It is given that, the side length of square is 20 inches.
Here a = 20 inches
Area = a²
= 20²
= 400
Therefore the correct answer is option a. 400
