Two identical circles, each with a radius of 7 cm, fit exactly side by side inside a rectangle. Each circle touches the other circle and three sides of the rectangle. What is the length of the rectangle?
- 14 cm
- 21 cm
- 28 cm
- 56 cm
Need a hint?
The length of the rectangle is the width of the two circles side by side.
Worked answer
- Diameter of each circle = 2 × 7 = 14 cm.
- Length of the rectangle = 2 diameters = 2 × 14 = 28 cm.
Answer: 28 cm
The mistake this question tests
Habit
Radius and diameter in circles
14 cm adds two radii. The rectangle is as long as two diameters.
How to fix it at home →Wrong answers children often give:
- 14 cm Radius and diameter in circles
- 56 cm Radius and diameter in circles
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