Question

the sides of a rectangle are in the ratio 3:7 and it's area is 1029m2. find its perimeter. ​

Answer 1

Given that sides of rectangle are in the ratio 3 : 7

So, let the common multiple be x

→ Sides would be 3x metre and 7x metre.

Given that area = 1029 m²

Now, we know that area = Length × Breadth

$\sf \implies 1029 = 3x \times 7x \\ \\ \sf \implies 1029 = 21x^2 \\ \\ \sf \implies x^2 = \frac{1029}{21} \\ \\ \sf \implies x^2 = 49 \\ \\ \sf \implies x = \sqrt{49} \\ \\ \sf \implies x = 7$

So, 3x = 3(7) = 21 m

and, 7x = 7(7) = 49 m

So, perimeter = 2(l + b)

→ perimeter = 2(21 + 49)

→ perimeter = 2(70)

→ perimeter = 140 metre.

$\huge \mathfrak{Answer \ 140 \ metres}$

Answer 2

✓let sides be x cm.

✓then sides are 3x and 7x.

✓area=1029cm

✓area of rectangle = length x breadth

✓1029= 3x x 7x

✓1029= 21x^2

✓x^2= 1029/21

✓x^2=49

✓x=√49

x=7

dimensions=3x= 3 X x= 21cm

7x= 7 X x= 49 cm

therefore, the dimensions are 21cm and 49 cm

Now perimeter =2(l+b)
=2(21+49)
=2x70
=140
Hence, perimeter is 140 m

Hope it helps Mark as brainliest one plzzz....