Question

The lengths of two sides of a triangle are $3$ cm and $4$ cm. Which of the following, can be the length of third side to form a triangle?

• A. $0.5$ cm
  
• B. $5$ cm
  
• C. $8$ cm
  
• D. $10$ cm
  

Answer 1

The correct option is B $5$ cm

(I) We know that $(3+4)$ cm is greater than third side.
Thus, the third side is smaller than $7$ cm
(ii) we know that $(4-3)$ cm is smaller than third side .
Thus, the third side is greater than $1$cm.
Therefore, $1$ cm < third side $<7$ cm.

Thus, $5$ cm can be the length of third side for a triangle.