Question

perimeter of a triangle is 18 cm and two of its sides 3.9cm and 5.8 cm. find the third side?​

Answer 1

Given: The perimeter of a triangle is 18 cm and two of its sides measure3.9 cm and5.8 cm respectively.

We have to find the third side of the triangle.

As we know that the perimeter of the triangle is calculated by a formula:

P = a + b + c

Where,

a = Side

b = Base

c = Side

We are solving in the following way:

Let assume the third side of the triangle be'x '.

We have,

The perimeter of a triangle is 18 cm and two of its si

des measure3.9 cm and5.8 cm respectively.

P = a + b + c

=> 18 = 3.9 + 5.8 + x

=> 18 = 9.7 +x => x = 18 - 9.7 => x = 8.3

Hence, the third side of the triangle will be

8.3

Answer 2

Answer:

Given that

perimeter(p) = 18cm

1 side(s1 )= 3.9cm

2 side(s2) = 5.8cm

3 side =p-(s1+s2)

=18-3.9-5.8

8.3cm