Give the lengths of the sides of a rectangle that cannot be divided into— two identical squares; three identical squares.
Rule for Two Identical Squares: A rectangle can be divided into two identical squares only if its length is twice its width (2:1 ratio).
Rule for Three Identical Squares: A rectangle can be divided into three identical squares only if its length is three times its width (3:1 ratio).
Examples that CANNOT be divided into two identical squares:
- 5 cm × 3 cm
- 7 cm × 4 cm
- 10 cm × 6 cm (Any rectangle where length 2 × width)
Examples that CANNOT be divided into three identical squares:
- 5 cm × 2 cm
- 8 cm × 3 cm
- 10 cm × 4 cm (Any rectangle where length 3 × width)
Explanation
The chapter establishes that for a rectangle to be divided into n identical squares, the ratio of length to width must be n:1. Any rectangle not satisfying this condition cannot be divided into n identical squares.
Solution Steps
For two identical squares: length must equal 2 × width (2:1 ratio)
For three identical squares: length must equal 3 × width (3:1 ratio)
Any rectangle where length 2 × width cannot be divided into two identical squares
Any rectangle where length 3 × width cannot be divided into three identical squares