Answer:
? = 35
Explanation:
The lengths of corresponding sides of similar polygons are in the same ratio.
The sides measuring 48 and 40 are corresponding sides.
The ratio of their lengths is 48/40.
The sides measuring 42 and ? are also corresponding, so they are in the same ratio.
That means we can set up a proportion to solve for the side with length ?.
48/40 = 42/?
Simplify the fraction on the left side.
6/5 = 42/?
Cross multiply.
6 * ? = 5 * 42
Divide both sides by 6.
? = 5 * 7
? = 35