The given measurement of the Instagram photo is "4" by "4". And a poster enlargement is being printed with a scale factor of 8.5 .
So on using the scale factor of 8.5 , lengths of new sides are "8.5 *4" by "8.5 *4"
= " 34" by "34" .
So the new lengths of the enlarged pictures are of dimension "34" by "34" .
It's a similar triangle so the ratios of corresponding sides should be equal which means
BC/EF = AB/DE
21/14 = AB/10
AB = 21/14 * 10 = 15 cm
100 because 99.9999 nearest to any number on there would be 100
6 and 8 I believe is the answer
