Question

two sides of isosecles triangle are each 9 meters less then twice the third side , if perimeter of triangle is 72 m .find the length of it's sides​

Answer 1

Answer:

Let the third side be x m.

Then the two equal sides are of length (2x−5) m.

Perimeter of triangle = 55 m.

⟹x+(2x−5)+(2x−5)=55

⟹5x−10=55

⟹x=13

Answer 2

Step-by-step explanation:

Given :-

Two sides of isosecles triangle are each 9 meters less then twice the third side and perimeter of triangle is 72 m .

To find :-

Find the length of it's ssides?

Solution :-

Let the length of the third side of an Isosceles triangle be X m

Twice of this side = 2X m

Length of the equal sides of the Isosceles triangle = 9 meters less then twice the third side

=> (2X-9) m

Perimeter of an Isosceles triangle =

(p) = 2a+b units

Where a is the length of the equal side and b is the another side.

On Substituting these values in the above formula then

=> P = 2(2X-9)+X m

=> P = 4X - 18 + X m

=> P = (5X-18) m

According to the given problem

perimeter of triangle is 72 m

=> (5X-18) = 72

=> 5X = 72+18

=> 5X = 90

=> X = 90/5

=> X = 18 m

The length of the third side = 18 m

Now,

2X-9 = 2(18)-9 = 36-9 = 27 m

Equal sides = 27 m and 27 m

Answer:-

The lengths of the three sides of the given Isosceles triangle are 27 m , 27 m and 18 m

Check:-

The three sides are 27 m , 27 m and 18 m

=> 27 = 36-9

=> 27 = 2(18)-9

=> 27 = 2×third side -9

Length of the equal sides of the Isosceles triangle = 9 meters less then twice the third side

and

Perimeter = 27+27+18 = 72 m

Verified the given relations in the given problem

Used formulae:-

Perimeter :-

The sum of the lengths of the all sides is its perimeter.

Perimeter of an Isosceles triangle :-

The equal sides are a units each and the third side is b units then the perimeter of the Isosceles triangle is (2a+b) units