Question

Problem 1 A 5 cm diameter hole is drilled in a 45 cm by 24 cm flat, rectangular piece of material a) Find the area of the rectangular piece after the circular hole is removed. b) What percent of the total area is removed from the rectangular piece?

Answer 1

The area of the rectangular piece is given by side x side

then,

Rectangular area:

the hole surface area is given by

`\pi* r^2\text{ where r: radius}`

`Then\text{ hole area: 19,63 cm}^2`

a) The area of the recetangular piece after the circular is removed is

Rectangular area - hole area =

`1060,37cm^2`

b) Percentage removed

`(19,63)/(1080)*100=1,8\text{ percent}`