The lengths of the sides of a rectangle are in ratio 5:3

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Question from todd, a parent:

the lengths of the sides of a rectangle are in ratio 5:3 the perimeter of the rectangle is 32 cm find the length of each side

Hi Todd.

If the width of the rectangle is 15, then its length is 15 x (5/3) = 25, and so its perimeter is 2 x (15+25) = 80.

If the width of the rectangle is w, then its length is w x (5/3) = 5w/3, and so its perimeter is 2 x (w + 5w/3) = 2 x (8w/3) = 16w/3.

Since you know the perimeter is 32, then 16w/3 = 32. What is w? What does that mean the length must be?

Cheers,
Stephen La Rocque.

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