Which of these four sets of side lengths will form a right triangle? Set 1
StartRoot 2 EndRoot cm, 9 cm, StartRoot 7 EndRoot cm

Set 2
2 in., StartRoot 5 EndRoot in., 9 in.

Set 3
StartRoot 6 EndRoot mm, 2 mm, 10 mm

Set 4
StartRoot 2 EndRoot ft, StartRoot 7 EndRoot ft, 3 ft

Set 1
Set 2
Set 3
Set 4

1. statement- ca is parallel to db and e is the midpoint of ad reason- given2. statement- reason- alternate interior angles3. statement- de is congruent to ae reason- definition of midpoint4. statement- triangle aec is congruent to triangle deb reason- asa (angle side angle)

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.