Question

Which of the following sets of side lengths form a triangle?

• A. 4 m, 3 m, 11 m
• B. 7 mm, 4 mm, 4 mm
• C. 3 cm, 1.1 cm, 5 cm
• D. 3 m, 4 m, 8 m

Answer 1

Answer: (B)

7 mm, 4 mm, 4 mm

A triangle can be formed only if sum of any two sides is greater than the third side.

In option $B$ sum of any two sides taken at a time is greater than the third side.

$7+4=11>4$

$4+4=8>7$

$4+7=11>4$
In all other options, sum of first two sides is less than the third side:
A) $4+3<11$
C) $3+1.1<5$
D) $3+4<8$

So option $B$ is correct.