Question

find the area of a rectangle whose length is twice the breadth and perimeter is 30 cm​

Answer 1

Let breadth = x

then length = 2x

Given, Perimeter = 30 cm

Therefore,

2(x+2x)=30

2×3x=30

x=30/6= 5cm

Area = l×b = x × 2x = 5 × 2×5 = 50 sq.cm

Answer 2

Answer:

Let the breadth be x and length be 2x

$x + 2x = 30 \\ 3x = 30 \\ x = \frac{30}{3} \\ x = 10$

$breadth = 10cm \\ length = 2 \times 10 \\ = 20cm$

$area = length \times breadth \\ = 10 \times 20 \\ = {200cm}^{2}$

$hope \: it \: helps$