Problema Solution

ABC has side lenghts of 10 units, 20 units, and 24 units. XYZ is similar to ABC and its longest side is 60 units in lenghts. What is the perimeter of XYZ?

Answer provided by our tutors

Since the triangles are similar we can find the scale factor by the formula:


scale factor = the longest side for XYZ / longest side of ABC


scale factor = 60 / 24


if we denote the scale factor with 'k' we can write


k = 60 / 24 = 5/2


then the sides of the similar triangle XYZ will be


XY = k*AB = (5/2)*10 = 25


YZ = k*BC = (5/2)*20 = 50


ZX = k*AC = (5/2)*24 = 60


and the perimeter of XYZ = XY + YX + ZX = 25 + 50 + 60 = 135 units.


Another way to solve this problem is by using the theorem : If two similar triangles have a scale factor of a : b, then the ratio of their perimeters is a : b.


Perimeter XYZ = scale factor * Perimeter ABC


Perimeter XYZ = (5/2) * (10 + 20 + 24) = 135 units.


The perimeter of XYZ is 135 units.