Question

The length of the rectangular field is thrice it's breadth. If perimeter is 400 mates. Find it's length and breath

Answer 1

${ Answer ~ is ~ l ~= ~150 m ~and ~b~=~50m}$

Step by step expiation :-

Here we have The length of the rectangular field is thrice it's breadth .

Let breath as $</strong><strong>{</strong><strong>x</strong><strong>}</strong><strong>$ than, length is equal to $</strong><strong>{</strong><strong>3</strong><strong>x</strong><strong>}</strong><strong>$.

Perimeter is 400 meters.

$</strong><strong>{</strong><strong>Perimeter</strong><strong>~</strong><strong>=</strong><strong>~</strong><strong>2</strong><strong>(</strong><strong>l</strong><strong>+</strong><strong>b</strong><strong>)</strong><strong>}</strong><strong>$

$400 = 2(l + b) \\ \\ 200 = 3x + x \\ \\ 200 = 4x \\ \\ x = \frac{200}{4} = 50 \: m$

$</strong><strong>{</strong><strong>length </strong><strong>~</strong><strong>=</strong><strong>~</strong><strong>3</strong><strong>x</strong><strong>~</strong><strong>=</strong><strong>~</strong><strong>1</strong><strong>5</strong><strong>0</strong><strong>~</strong><strong>m</strong><strong> </strong><strong>\</strong><strong>\</strong><strong> </strong><strong>breath</strong><strong>~</strong><strong>=</strong><strong>~</strong><strong>x</strong><strong>~</strong><strong>=</strong><strong>~</strong><strong>5</strong><strong>0</strong><strong>~</strong><strong>m</strong><strong> </strong><strong>}</strong><strong>$

Answer 2

l=3b

perimeter=2(l+b)

2(l+b)=400

2(3b+b)=400

2(4b)=400

4b=400÷2

b=200÷4

=50

ie,

b=50

l=3b

=3×50

=150