Which of these four sets of side lengths will form a right triangle?

Set 1
6 cm, 7 cm, StartRoot 12 EndRoot cm

Set 2
8 in., StartRoot 29 EndRoot in., StartRoot 35 EndRoot in.

Set 3
StartRoot 3 EndRoot mm, 4 mm, StartRoot 5 EndRoot mm

Set 4
9 ft, StartRoot 26 EndRoot ft, 6 ft

Set 3 I believe is correct

 C (Set 3 is correct

Step-by-step explanation:

graph b

step-by-step explanation:

one solution- graph a (clear intercepting point.)

no solution- graph b (they're parallel, there will never be a point of interception.)

infinite solutions- graph c (all points intercept.)