Mathematical Reasoning
A rectangle has a perimeter of 40 cm. If its length is 4 cm longer than its width, what is the area of the re…
Question 1 · Multiple choice
Question
A rectangle has a perimeter of 40 cm. If its length is 4 cm longer than its width, what is the area of the rectangle?
Options
- A. 84 cm²
- B. 96 cm²
- C. 100 cm²
- D. 80 cm²
- E. 144 cm²
Correct answer
B. 96 cm²
Explanation
The rectangle has perimeter 40 cm. Use the perimeter formula: 2(length + width) = 40 Divide both sides by 2: length + width = 20 We are told the length is 4 cm longer than the width. So let width = w. Then length = w + 4. Substitute: w + (w + 4) = 20 2w + 4 = 20 2w = 16 w = 8 So the width is 8 cm and the length is: 8 + 4 = 12 cm Now find the area: 12 x 8 = 96 cm^2 So the area is 96 cm^2.