Question

How many different rectangles with an area of 20 cm² are possible, if each side length is a whole number of centimetres? What is the perimeter of each rectangle?

please help me.
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Answer 1

3 rectangles:

20x1, perimeter 42

10x2, perimeter 24

5x4, perimeter 18

Explanation:

area = width * length

perimeter = 2*(width + length)

You can start by finding the divisors of 20, which are:

1, 2, 4, 5, 10, 20.

Then for each of them work out the width and length, and eliminate duplicates (4x5=5x4).

Answer 2

Answer: 6 rectangles. Perimeters: 42, 24, 18

Step-by-step explanation: There are 3 different ways to get 20 cm for your area, 20x1, 10x2, and 5x4. Then you add the inserves to get the other 3 rectangles: 1x20, 2x10, and 4x5. Then for the perimeter just take the two sides, add them, then multiply times two. 20+1=21 21*2=42 and so on for the others, to give you the perimeters of 42, 24, and 18.