calculate the cuboid 4

A rectangular box has a surface area of 228.6 cm², a length of 4.5 cm and an height of 7.2 cm.

a) calculate the widt

b) calculate the volume

a) answer width

A = 2 * l * w + 2 * l * h + 2 * w * h 

228.6 = 2*4.5*w + 2*w*7.2 + 2*4.5*7.2

228.6 = 9*w + 14.4*w + 64.8    / – 64.8 

163.8 = w * (9 + 14.4) 

163.8 = w * 23.4     / : 23.4

w = 7 cm 

A: The width is 7 cm.