Class 10 Board-Style Challenge: Exposed Surfaces

Surface Areas and VolumesStep 1 of 3

Question

Which surfaces are actually exposed? Solve each object before moving to the next one. The touching faces are hidden.
total length 17 cmr = 3.5 cm

Total length 17 cm · radius 3.5 cm

exposed outside hidden join

A capsule-shaped model has total length 17 cm17\text{ cm} and radius 3.5 cm3.5\text{ cm}. It is a cylinder with one hemisphere at each end. What is its total outer surface area? Use π=227\pi=\dfrac{22}{7}.

What you will learn

Identify every painted outer surface, exclude hidden joins, and calculate the area for three different joined solids.

Common mistake to avoid

Adding the total surface areas of the separate solids counts circular faces that are hidden after joining.

Helpful?