The area of the rectangular piece is given by side x side
then,
Rectangular area:
[tex]45\operatorname{cm}\times24\operatorname{cm}=1080\operatorname{cm}[/tex]the hole surface area is given by
[tex]\pi\times r^2\text{ where r: radius}[/tex][tex]r=\frac{diameter}{2}=\frac{5\operatorname{cm}}{2}=2,5\text{ cm}[/tex][tex]Then\text{ hole area: 19,63 cm}^2[/tex]a) The area of the recetangular piece after the circular is removed is
Rectangular area - hole area =
[tex]1060,37cm^2[/tex]b) Percentage removed
[tex]\frac{19,63}{1080}\times100=1,8\text{ percent}[/tex]