Question

the perimeter of an isosceles triangle is 131 by 20 CM if one of its equal sides is 7 by 5 cm find the third side​

Answer 1

Let the third side be X

now, 7/5 +7/5 + X = 131/20

14/5 + X = 131/20

X = 131/20 - 14/5

X = 131-56/5

X = 75/5 = 15 cm

Answer 2

The third side is 15/4

Step-by-step explanation:

We are given that one of its equal sides is $\frac{7}{5}$

$a=\frac{7}{5}\\b=\frac{7}{5}\\c=?$

Perimeter of triangle = a+b+c

Perimeter of triangle =$\frac{7}{5}+\frac{7}{5}+c$

We are given that the perimeter of an isosceles triangle is 131 by 20 CM

So,$\frac{7}{5}+\frac{7}{5}+c=\frac{131}{20}\\c+\frac{14}{5}=\frac{131}{20}\\c=\frac{131}{20}-\frac{14}{5}\\c=\frac{15}{4}$

Hence The third side is 15/4

#Learn more:

The sides of a triangle are 131/2 m, 113/4m and 3 1/8m. find its perimeter.

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