Question

the parallel sides of trapezium are in the ratio of 2:3. its height is 8cm and area is 240cm2, find its perimeter

Answer 1

Answer:

80cm

Step-by-step answer:

Let the ratio be 2x and 3x

Area of the trapezium=½×(2x+3x)×height

240 cm²=½×(5x)×8

240=5x×4

Therefore,

x=12

AB=2x=2×12=24cm

CD=3x=3×12=36cm

DE=CD(By using congruency of triangles RHS)

DE=CF=(3x-2x) ×½=(36-24)×½=6cm

In ∆AED

AE²+DE²=l²

8²+6²=l²

64+36=l²

100=l²

√100=√l²

l=10cm

Perimeter of the trapezium=2x+3x+10+10

=24+36+10+10

=80cm