A rectangle's length is 3 cm more than its width, and its area is 70 cm². What is its perimeter?
Answer and explanation
Correct answer: D. 34 cm, from sides 7 cm and 10 cm
Answer: 34 cm. Why not the others: 17 is half the perimeter; 6 x 9 = 54 and 8 x 11 = 88 do not give an area of 70.
- Step 1: Let the width be : , so .
- Step 2: Factorise: , so and length = 10.
- Step 3: Perimeter: 2(7 + 10) = 34.
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