Question

In the figure AB is parallel to CD. If the ratio of the perimeter of BEA to that of CED is 3:5 and the sum of the perimeters is 320, find the perimeter of each triangle.

A. perimeter of CED= 192 perimeter of BEA= 128
B. perimeter of CED= 120 perimeter of BEA= 200
C. perimeter of CED= 200 perimeter of BEA= 120
D. perimeter of CED= 128 perimeter of BEA= 192

Answer 1

Can someone give me a formula to find both perimeters?

Answer 2

let the respective perimetrs be 3x and 5x and
3x+5x=320
and so on..

Answer 3

With the information that AB is parallel to CD, we have SIMILAR TRIANGLES, so that corresponding parts are proportional. That is all we need to know.

perimeter of CED = m
perimeter of BEA= n
m > n

This gives: \(\dfrac{n}{m} = \dfrac{3}{5} \rightarrow 3m=5n\)

We also know that m + n = 320

That is a wealth of information. Solve away!!

Answer 4

Thanks to both of you!

Answer 5

I got, C!