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

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a

When george started his current job, his employer told him that at the end of the first year, he would receive two vacation days. after each year worked, his number of vacation days will double up to five work weeks (25days) of payed vacation. how many vacation days will he have in 4 years

What is the length and width of a 84.5 square foot rug? will mark