Problema Solution

A coin of circle shape has a radius of 3 cm with a square of side x cm removed from its center. The area of each face of the coin is 7(pi) cm2.

Form an equation in x and solve the equation.

Answer provided by our tutors


R = 3 cm the radius of the circle

A = 7pi cm^2 the area of the face of the coin

A1 = area of the circle

A2 = x^2 area of the square

A = A1 - A2

The area of the circle is:

A1 = R^2*(pi)

A1 = (3)²(pi)

A1 = 9(pi) cm²

If we plug the value for the areas into A = A1 - A2 we get:

9(pi) - x^2 = 7(pi)

If we solve the above equation with pi = 3.14, then we get, 


x =2.506 cm approximately

Click here to see the step by step solving for 'x'