Hidden Faces Challenge

Surface Areas and VolumesStep 1 of 3

Question

A hemisphere of radius 3 cm is mounted on a cube of edge 10 cm. Find the exposed surface area in terms of π.
a = 10 cm
cube: 600
− 9π
+ 18π

Which area on the cube becomes hidden?

What you will learn

Decompose a composite solid into visible surfaces and remove the matching contact regions hidden at the join.

Common mistake to avoid

Simply adding two total surface areas counts both contact faces even though neither face remains exposed.

Make this mistake visible
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