E2.6 Apply the formula for the area of a rectangle to find the unknown measurement when given two of the three.
Skill: Using the Formula for the Area of a Rectangle to Find an Unknown Measurement
Once the student understands the concept of an array related to the area formula, they are able to understand the relationship between the different measurements of the rectangle and thus use them to find an unknown measurement.
Both multiplication and division can be used to solve problems involving the area of a rectangle.
- Multiplication is used to determine the unknown area when the base and height of a rectangle are given (Area = base × height).
- Division is used to determine either the length of the base or the length of the height when the total area is given (Area ÷ base = height; Area ÷ height = base).
- Either side length can be considered the base or the height of a rectangle.
Source: The Ontario Curriculum. Mathematics, Grades 1-8 Ontario Ministry of Education, 2020.
Knowledge: Formula for the Area of a Rectangle
The formula for finding the area of a rectangle can be generalized to describe the relationship between a rectangle’s side lengths and its area: (Area = base × height).
Source: The Ontario Curriculum. Mathematics, Grades 1-8 Ontario Ministry of Education, 2020.