The length of third side of triangle should be greater than 2 cm and less than 38 cm
Solution:
Given that,
Jamal has 2 straight sticks with the length of 20 cm and 18 cm
Jamal searches for a third stick so that he can form a triangle
According to triangle inequality theorem,
Triangle inequality theorem states that sum of length of two sides of triangle should always be greater than measure of third side
Let the length of unknown side be "x"
Case 1:
Let 20 cm be the length of third side
Then,
x + 18 > 20
x > 20 - 18
x > 2
Case 2:
Let "x" cm be the length of third side
18 + 20 > x
38 > x
x < 38
This means that length of third side of triangle should be greater than 2 and less than 38