Question

Which set of side lengths will not form a right triangle?


5, 12, 13
7, 24, 25
9, 16, 20
8, 15, 17

Answer 1

take the longest side, square it and see if this equals sum of squares of the other 2 sides

(pythagoras)

first one forms a right angles triangle because 13^2 # 169
and 5^2 + 12^2 = 25 + 144 = 169

Answer 2

9, 16, 20

The others are all sets that do. You will know them by heart by the end of Geometry.

Answer 3

25+144= 169
49+576 = 625
64+ 225 = 289

(That is why the others work)