Question

Each side of a triangle is increased by 10 cm. If the ratio of perimeter of the new Triangle and the given triangle is 5:4. find the perimeter of the given Triangle.

Answer 1

Let the sides of old triangle be a,b and c resp.

Sides of new triangle=(a+10),(b+10),(c+10)

Ratio of perimeters of both triangles=5:4

$\frac{a + 10 + b + 10 + c + 10}{a + b + c } = \frac{5}{4} \\ 4(a + 10 + b + 10 + c + 10) = 5( a + b + c) \\ 4a + 4b + 4c + 120 = 5a + 5b + 5c \\ 5a + 5b + 5c - 4a - 4b - 4c = 120 \\ a + b + c = 120cm$

Perimeter of old triangle=120cm

Perimeter of new triangle=150cm

Thank You.

Please mark as brainliest.

Answer 2

Answer:

120 cm

Step-by-step explanation:

Each side by increased by 10 cm.

Let x be the original perimeter .

So new perimeter = x + 30 .

( x + 30 ) / x = 5 / 4

= 4 x + 120 = 5 x

= x = 120

Hence the original perimeter was 120 cm.