Arectangle has a width of 5 meters and a length of 7 meters. a similar rectangle has a width of 15 meters. what is the length of the similar rectangle?

I believe 21 because 5×3 is 15 so 7×3=21

You can figure this out by using a form of what equal what if the width is 5 and the other 15 five goes into 15 three times so the length is 21

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)