We are given information that the two triangles are similar and we want to work out the length of "t" . Since these 2 triangles are similar, it means that a scale factor is used to enlarge the sides, we can work out the scale by dividing QP by LJ and RP by KJ so,
QP ÷ JK = 25 ÷ 5 = 5
RP ÷ JL = 22.5 ÷ 4.5 = 5
So we can see the scale factor is 5, now all we need to do is multiply the scale factor by 1.5 to find the value of t
