Unit 8, Lesson 14
Edge Lengths and Volumes
Grade 8
14.2
Activity
Fill in the missing values using the information provided:
| sides | volume | volume equation |
|---|---|---|
| 27 in3 | ||
|
in |
||
Student Lesson Summary
For a square, its side length is the square root of its area. For example, this square has an area of 16 square units and a side length of 4 units.
Both of these equations are true:
For a cube, the edge length is the cube root of its volume. For example, this cube has a volume of 64 cubic units and an edge length of 4 units:
Both of these equations are true:
is pronounced “the cube root of 64.” Here are some other values of cube roots:
because
because
because
The cube root of a number is the number whose cube is . It is also the edge length of a cube with a volume of . The cube root of is written as .
The cube root of 64 is written as . Its value is 4 because is 64.
is also the edge length of a cube that has a volume of 64.