Question

The perimeter of a rhombus is 20 cm and one of its diagonals is 6 cm long. Find the length of the other diagonal.

Answer 1

let a  be the side of rhombus
perimeter of  rhombus= 20cm
4a =20
a = 5
diagonals of rhombus bisect each other at 90
hypo.²=height²+base²
25=9+base²
4= base
second diagonal is 4+4=8cm

Answer 2

Answer:

8 cm

Step-by-step explanation:

let the side of rhombus be 'a'cm and it is give. that perimeter is 20 CM hence the side will be:-

4a=20cm

a=5cm

And we know that diagonals of rhombus bisect each other at 90° and one of its diagonal is 6 CM let's find other using Pythagoras theorum

hypoteneus= 5cm, one side=3cm(as diagonals bisect each other) and other side be 'a' then

-> Hypo²=per²+base²

-> 5²=3²+a²

->25=9+a²

-> a²=16

-> a=4cm

and finally other diagonal =4+4=8cm