Compare the given dimensions of four triangles. Which triangle is possible to construct?

side lengths of 5 ft, 12 ft, and 13 ft
side lengths of 2 ft, 11 ft, and 15 ft
side lengths of 3 ft, 7 ft, and 11 ft
side lengths of 4 ft, 8 ft, and 15 ft

1 answer

To determine whether a triangle can be constructed with given side lengths, we can use the triangle inequality theorem. This theorem states that for any triangle with sides of lengths \(a\), \(b\), and \(c\):

  1. \(a + b > c\)
  2. \(a + c > b\)
  3. \(b + c > a\)

We will apply this theorem to each set of side lengths.

  1. Side lengths of 5 ft, 12 ft, and 13 ft:

    • \(5 + 12 = 17 > 13\)
    • \(5 + 13 = 18 > 12\)
    • \(12 + 13 = 25 > 5\)
    • All conditions are satisfied; therefore, this triangle can be constructed.
  2. Side lengths of 2 ft, 11 ft, and 15 ft:

    • \(2 + 11 = 13 \not> 15\)
    • One of the conditions fails; therefore, this triangle cannot be constructed.
  3. Side lengths of 3 ft, 7 ft, and 11 ft:

    • \(3 + 7 = 10 \not> 11\)
    • One of the conditions fails; therefore, this triangle cannot be constructed.
  4. Side lengths of 4 ft, 8 ft, and 15 ft:

    • \(4 + 8 = 12 \not> 15\)
    • One of the conditions fails; therefore, this triangle cannot be constructed.

In conclusion, the only triangle that can be constructed is the one with side lengths of 5 ft, 12 ft, and 13 ft.