Question

the adjacent sides of parallelogram in the ratio 5:3 if the longer of the two side is 7.5 cm find the perimeter of parallelo gram

Answer 1

Adjacent sides=5:3
=5x,3x

Longer side = 5x
=7.5cm

Therefore,X=7.5/5
=1.5cm

3x = 1.5*3
=4.5cm

Hence, perimeter of parallelogram=7.5+4.5+7.5+4.5(opposite sides of parallelogram are equal)
=>24cm

Answer 2

Answer:

perimeter = 24cm

Step-by-step explanation:

Given

• Ratio of adjacent sides of parallelogram are in ratio 5:3.

• Length of longer side = 7.5cm.

To Find :

• Perimeter of parallelogram = ?

Assumption :

• Assuming length of longer side = 5x

• Length of shorter side = 3x

We already know that the length of longer side is 7.5cm.

So ,

$\implies \: 5x = 7.5$

☞ Value of x will be :

$\implies \: x = 7.5 \div 5$

$\implies \: x = 1.5cm$

Now , as assumed earlier :

→ Length of smaller side = 3x = 3 × 1.5 = 3.5

Now , Perimeter = 2(l + b)

→ Perimeter = 2(7.5 × 4.5)

→ Perimeter = 2(12)

→ Perimeter = 24cm.

☞ It was a parallelogram , then why did we used formula of rectangle ?

Answer : Because in a parallelogram , adjacent sides remain same. So here , we can use a formula of a rectangle.

What you need to know ?

• Perimeter of a polygon is sum of all sides.