Question

The adjacent sides of a parallelogram are in the ratio 3:7 and its perimeter is 100cm. Find the sides of the parallelogram.

Answer 1

Let the adjacent sides of the parallelogram are 3x and 7x.
We know that, the opposite sides of a parallelogram are equal.
Hence, the other two adjacent sides are also 3x and 7x.
Given perimeter = 100 cm
⇒ 3x + 7x + 3x + 7x = 100 cm
⇒20x = 100
⇒ x = 5

The sides are 15 cm, 35 cm, 15 cm and 35 cm.

Answer 2

the perimeter of a parallelogram is 2(l=b). the opposite sides are equal in length.
so, this information can be put in an equation as-
2(7x+3x)=100
now, we will open the brackets.
14x+6x=100
20x=100
now, we will leave x to one side and shift 20  to rhs
x=100/20 which implies x=5

now it is very easy to find the sides of the parallelogram, as we now know the value of x.
the sides are 7x and 3x
7*5 and 3*5
which is equal to 35 and 15.
DONE!!!!!!!!!!!!!!!!!