Question

ABCD is a parallelogram, and BC is twice the length of AB. If the perimeter of ABCD is 360 cm, find the length of AD.

• A. 60 cm
• B. 80 cm
• C. 100 cm
• D. 120 cm

Answer 1

The correct option is D 120 cm


Given, ABCD is a parallelogram.

Length of AB = x (Assumption)
Then, Length of BC = 2x.
Perimeter of ABCD = 360 cm (Given)

Perimeter of the parallelogram = AB + BC + CD + DA
$\Rightarrow$ 360 = x + 2x + x + 2x
$\Rightarrow$ 360 = 6x
$\Rightarrow$ x = $\frac{360}{6}$ = 60

Length of AB = 60 cm
Length of BC = 2 $\times$60 = 120 cm.
Length of BC = Length of AD = 120 cm

Hence, Length of AD = 120 cm.