This is the concept of area of solid materials, we are required to calculate the total area of horsehide that is required to cover 100 balls with each having a circumference of 9 in. The area of hide required will be given by: area=(area of each ball)*(total number of balls) area of each ball is given by: SA=4πr^2 given that the circumference is 9in, we are required to find the radius of the ball Circumference, c=2πr thus; 9=2πr r=9/(2π) r=1.4 in Therefore the surface area will be: SA=4π*1.4^2=24.6 in^2 Therefore the area of horsehide required to cover 100 balls will be: Area=24.6*100=2,460 in^2.