What instrument is used to measure mass? scale balance massometer graduated cylinder

Aregular pentagon with a perimeter of 21 inches is dilated by a scale factor of 5/3 to create a new pentagon. what is the perimeter of the new pentagon?

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

Asquare and an equilateral triangle have the same perimeter. each side the triangle is 4 inches longer than each side of the square. what is the perimeter of the square