Question 1113073
The coin is in the shape of a circle of radius 3 cm with a square of sides x cm removed from its centre.
 The area of each face of the coin is 7pi cm^2. 
 i) form an equation in x and show that it reduces to 2pi-x^2=0.
{{{pi*3^2 - x^2}}} = {{{7*pi}}}
{{{9pi - x^2}}} = {{{7pi}}}
{{{9pi - 7pi - x^2 = 0}}}
{{{2pi - x^2}}} = 0
:
 ii) solve the equation 2pi-x^2=0.
{{{x^2 = 2pi}}}
x = {{{sqrt(2pi)}}}
:
 iii) find the perimeter of the square
p = {{{4sqrt(2pi)}}}