Calculate the surface area and volume of the shape below. You can assume the shape on top is a regular (circular) cylinder,
Answer to the nearest whole unit
4cm
Зcm
..
8cm
5cm
15cm

Surface area

Let's calculate the surface area of the rectangular block. It has length, width and height of L = 15, W = 5, H = 8. The surface area is going to be

SA = 2*(LW+WH+LH)

SA = 2*(15*5+5*8+15*8)

SA = 470

This is without the cylinder attached to the top surface. If we account for that, then we'll have to subtract off the area of the circle covered up which is

pi*r^2 = pi*3^2 = 9pi = 28.27433 approximately

So 470-28.27433 = 441.72567 is the approximate surface area of the rectangular block after we subtract off the circular portion covered up by the cylinder.

The lateral surface area of the cylinder is approximately

2*pi*r*h = 2*pi*3*4 = 24pi = 75.39822

Which adds onto the top circular area of 28.27433 to get 28.27433+75.39822 = 103.67255

Meaning that 103.67255 is the surface area for the cylinder portion. Again we don't worry about the bottom portion as it's not part of the outer surface.

Overall, the total surface area of this compound 3D figure is

(surface area for rectangular portion) + (surface area cylinder portion) = 441.72567+103.67255 = 545.39822

When rounding to the nearest whole number, the total surface area is about 545 square cm

Volume

The rectangular block has volume L*W*H = 15*5*8 = 600 cubic cm

The cylinder has volume pi*r^2*h = pi*3^2*4 = 113.0973355 approximately

Add the two volumes to get 600+113.0973355 = 713.0973355 and this rounds to 713. We don't have to do any subtraction in this section.

good luck!

cutie~