Area of a rectangle
Answers are for parents and teachers.
1
A rectangle has area 135 cm² and length 15 cm. How wide is it (cm)?
9
2
The length of a rectangle is 3 times its width and the perimeter is 64 cm. What is the area (cm²)?
192
3
A room is 6 m by 5 m. How many square tiles with side 50 cm are needed to cover it?
120
4
Each side of a 10 cm by 6 cm rectangle is made 2 cm longer. By how many cm² does the area grow?
36
5
Write the idea of the proof of the rectangle area formula in your own words.
Cut a square of side a + b into two squares and two equal rectangles; adding the areas gives S = ab.