Classify each triangle as acute, right, or obtuse.

10, 16, 2sqrt39

1 answer

To classify the triangle with side lengths \(10\), \(16\), and \(2\sqrt{39}\), we need to determine the relationship between the squares of the lengths of the sides.

  1. First, let's denote the sides:

    • \(a = 10\)
    • \(b = 16\)
    • \(c = 2\sqrt{39}\)
  2. Calculate \(c^2\): \[ c^2 = (2\sqrt{39})^2 = 4 \cdot 39 = 156 \]

  3. Calculate \(a^2\) and \(b^2\): \[ a^2 = 10^2 = 100 \] \[ b^2 = 16^2 = 256 \]

  4. Now, we compare \(a^2 + b^2\) with \(c^2\): \[ a^2 + b^2 = 100 + 256 = 356 \]

  5. Now we compare:

    • If \(a^2 + b^2 < c^2\), the triangle is obtuse.
    • If \(a^2 + b^2 = c^2\), the triangle is right.
    • If \(a^2 + b^2 > c^2\), the triangle is acute.

Since \(356 > 156\), we conclude that: \[ a^2 + b^2 > c^2 \]

Thus, the triangle is classified as acute.