Which set of side lengths forms a right triangle?

2, 3, 13
4, 6, 10
9, 12, 18
15, 36, 39

1 answer

To determine which set of side lengths forms a right triangle, we can use the Pythagorean theorem, which states that for a right triangle with sides \( a \), \( b \), and hypotenuse \( c \):

\[ c^2 = a^2 + b^2 \]

We need to check each set of lengths to see if this condition holds.

  1. Set: 2, 3, 13

    • Hypotenuse \( c = 13 \)
    • \( 13^2 = 169 \)
    • \( 2^2 + 3^2 = 4 + 9 = 13 \) (not equal to 169)
  2. Set: 4, 6, 10

    • Hypotenuse \( c = 10 \)
    • \( 10^2 = 100 \)
    • \( 4^2 + 6^2 = 16 + 36 = 52 \) (not equal to 100)
  3. Set: 9, 12, 18

    • Hypotenuse \( c = 18 \)
    • \( 18^2 = 324 \)
    • \( 9^2 + 12^2 = 81 + 144 = 225 \) (not equal to 324)
  4. Set: 15, 36, 39

    • Hypotenuse \( c = 39 \)
    • \( 39^2 = 1521 \)
    • \( 15^2 + 36^2 = 225 + 1296 = 1521 \) (equal to 1521)

The set 15, 36, 39 forms a right triangle, as it satisfies the Pythagorean theorem.