In each case, determine if the sides form a right triangle. if they do, place in the yes column. if not, place them in the no column.

Use the Pythagorean Theorem to determine if the sides form right triangle or not.
a^2+b^2=c^2

3,4,5
3^2+4^2=5^2
9+16=25
25=25
Yes

5,12,13
5^2+12^12=13^2
25+144=169
169=169
Yes

6,8,10
6^2+8^2=10^2
36+64=100
100=100
Yes

6,9,12
6^2+9^2=12^2
36+81=144
117=144
No

8,13,26
8^2+13^2=26^2
64+169=676
233=676
No

8,15,17
8^2+15^2=17^2
64+225=289
289=289
Yes

9,12,14
9^2+12^2=14^2
81+144=196
221=166
No

5/2,6,13/2
(5/2)^2+6^2=(13/2)^2
25/4+36=169/4
25/4+144/4=169/4
169/4=169/4
Yes

N- 3 is the answer