15. Rectangle ABCD has a perimeter of 24 centimetres. Sides AB and DC are twice as long as sides AD and BC. square C Calculate the length of side AD. Do not use a ruler. cm

## Step1: The perimeter of a rectangle, which is the sum of the lengths of all its four sides, can be given as twice the sum of width and height. Given this rule, we can derive an equation.Given that the perimeter is 24 cm and \( AB, DC = 2(AD, BC) \)## Step2:From the problem it's given that sides and are twice as long as sides and . Forming these into an equation the perimeter constant, we get:### \( 2(AD + AB) = P \)Here =x (assuming the same because the length of the sides are same )And =2x## Step3:Now plug in and into the equation and solve for x:### \( 2(x + 2x) = 24 \)which simplifies to \( 2(3x) = 24 \).## Step4: Finally, divide both sides by 6 to solve for x : ###