The sum of the length of the two sides of the triangle must be greater than the length of the third side.
A.
34 + 75 = 109 > 100
34 + 100 = 134 > 75
75 + 100 = 175 > 34
CORRECT!
B.
16 + 21 = 37 < 47 NOT
C.
8 + 24 = 32 < 33 NOT
D.
1 + 2 = 3 NOT
Answer: A. 34 mm, 75 mm, and 100 mm
