Find Length of square:
Area of square = 400
Length = √400 = 20
Find coordinate c:
Therefore the coordinate of c = (20÷2, 20) = (10, 20)
Solve a:
Plug (10, 20) into the equation y = ax² + 10 to solve for a:
20 = a(10)² + 10
20 = 100a + 10
100a = 10
a = 0.1
Answer: Value of a = 0.1