Question

find the third side of triangle if perimeter of triangle is 80CM one side is 20cm and second side of triangle is 40 cm​

Answer 1

Answer:

The third side of the triangle measures 20 cm.

Step-by-step explanation:

Measure of first side = 20 cm

Measure of second side = 40 cm

Given, perimeter = 80 cm

We know that,

Perimeter = Sum of the sides

80 cm = 20 cm + 40 cm + Third side

or, 80 cm = 60 cm + Third side

or, 80 cm - 60 cm = Third side

or, 20 cm = Third side

Answer 2

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Given a triangle having sum of its all three sides (i.e Perimeter of Triangle) = 80 cm.

One side = 20 cm ; Second side = 40 cm

Perimeter of Triangle = Sum of its all three sides

Perimeter of Triangle = 80 cm (given)

80 = 20 + 40 + Third side

Let measure for the third side be x cm

80 = 60 + x

x = 80 - 60 = 20 (x = 20)

Therefore, 20 cm is the required measure for the third side of a Triangle