Question

A rectangle has length equal to twice its width. The perimeter of it is 150cm. Find the length of the rectangle.

Answer 1

The total of length and width is half the perimeter, so is 75 cm. The length makes up 2/3 that amount, or 50 cm.

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If you have a ratio 2:1 = length:width, then length will be 2 of the total of 2+1 = 3 parts, or 2/3 of the total.