Question

If these triangles are similar, what is the length of side DF?

A) 3 u
B) 2.4 u
C) 2 u
D)5/3 u

Answer 1

B

Explanation:

Answer 2

Triangles are similar, so:


`(|AB|)/(|DE|)=(|AC|)/(|DF|)\\\\\\(2,5)/(1,5)=(4)/(|DF|)\\\\\\ 2,5\cdot|DF|=1,5\cdot4\quad|:2,5\\\\\\|DF|=(1,5\cdot4)/(2,5)=(6)/(2,5)=(6)/(2,5)\cdot(4)/(4)=(24)/(10)=2(4)/(10)=\boxed{2,4\,u\qquad[\text{B}]}`