What is the width of the margin on the bottom?

Question

A painting measuring 120 cm wide by 80 cm tall is mounted on a picture frame. It leaves a 6 cm wide margin at the top and each side of the painting. If the painting is similar to the frame, what must the width of the margin at the bottom of the painting be?

Answer 1

The width of the frame is 96 cm. The ratio between the width of the frame and the width of the frame is 96/80. 

The ratio between the height of the frame and the height of the picture is x/120. These two must be equal.

 

96 / 80 = x / 120

x = 144                This is the height of the fram

 

144 - 120 - 6 = 18

 

The margin ar the bottom is 18 cm.