A square has a perimeter of 28 cm. All dimensions are increased by a scale factor of 3 to create a similar figure. What would be the perimeter of the new figure?
First, find the length of one side of the square. You do this by dividing the perimeter by 4 to find the individual lengths.
Therefore each side of the square is 7cm long. You are increasing all sides by a scale factor of 3. This gives each side a length of 21cm.
To find the new perimeter you need to multiply one side of the square by 4. Therefore the perimeter will be 84cm.