Question

The sides of a triangle are in the ratio 3:5:7 and its perimeter is 45 cm. What are the lengths of the sides ?​

Answer 1

Answer:

Given sides in the ratio 3:5:7

perimeter of the triangle =60cm

3x+5x+7x=60

⇒15x=60

⇒x=60/15

⇒x=4

3x=3×4=12cm

5x=5×4=20cm

7x=7×4=28cm

S=

2

1

(a+b+c)

=

2

1

⋅60

=30

Area =

30(30−12)(30−20)(30−28)

=

30⋅18⋅10⋅2

=

60⋅180

=

10800

=

3600⋅3

=60

3

cm

2

∴ Area of triangle =60

3

cm

2

.