Question

two sides of a triangle are 80 cm and 13 cm the perimeter of triangle is 42 cm find its third side​

Answer 1

Correct Question:

• Two sides of a triangle are 8 cm and 13 cm. The perimeter of triangle is 42 cm. Find its third side.

Answer:

$\large\bold\red{21\:cm}$

Explanation:

Let,

The third side be 'c' cm.

Now,

Given,

A triangle having side Length,

• a = 8 cm
• b = 13 cm

And,

• Perimeter, p = 42 cm

But,

We know that,

• Perimeter of a triangle is the sum of all the three sides.

Therefore,

We get,

$= > p = a + b + c \\ \\ = > 42 = 8 + 13 + c \\ \\ = > 21 + c = 42 \\ \\ = > c = 42 - 21 \\ \\ = > c = 21$

Hence,

Length of the third side is 21 cm