Lesson: Surface Areas of Composite Solids Mathematics • 7th Grade

In this lesson, we will learn how to find the surface area of a composite solid using the formulas for lateral or total surface areas of a single solid.

Lesson Plan

Students will be able to

find the surface areas of composite solids where two solids have been joined together,
find the surface areas of composite solids where one solid has been removed from another,
solve real-world problems by finding the surface areas of composite solids.

Lesson Video

Lesson Worksheet

Q1:

The given figure is made by placing a cube of side length 13 cm on the top of another cube of side length 18 cm. Find its surface area.

Q2:

If a part of a cube, whose edge length is 7 cm, is cut to form a cuboid with side lengths of 3 cm, 4 cm, and 4 cm, find the surface area of the remaining part of the cube.

Q3:

The object shown is made from two cubes, one of side 3.3 cm, and the other 1.2 cm. If you must paint this object (including the base of the combined solid), what area do you report?