Classify each triangle as acute, right or obtuse.

10, 16, 239−−√

(1 point)
These side lengths form a(n)
triangle.

1 answer

To classify the triangle using the side lengths \( a = 10 \), \( b = 16 \), and \( c = \sqrt{239} \) (assuming \( c \) is the longest side), we will use the properties of triangles and the Pythagorean theorem.

  1. Check if it's a triangle: We need to ensure that it satisfies the triangle inequality:

    • \( a + b > c \)
    • \( a + c > b \)
    • \( b + c > a \)

    Calculating using \( c = \sqrt{239} \):

    • Is \( 10 + 16 > \sqrt{239} \)?
      • \( 26 > \sqrt{239} \) → \( 26^2 > 239 \) → \( 676 > 239 \) → True.
    • Is \( 10 + \sqrt{239} > 16 \)?
      • We need \( \sqrt{239} > 6 \).
      • \( 239 > 36 \) → True (since \( 15.5^2 = 240.25 \)).
    • Is \( 16 + \sqrt{239} > 10 \)?
      • Always true since both numbers are positive.

    So, it can be formed as a triangle.

  2. Classify the triangle: To classify whether it's acute, right, or obtuse, we will compare the squares of the sides.

    We need to check the following:

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

    First, calculate \( a^2 \), \( b^2 \), and \( c^2 \):

    • \( a^2 = 10^2 = 100 \)
    • \( b^2 = 16^2 = 256 \)
    • \( c^2 = (\sqrt{239})^2 = 239 \)

    Now compute \( a^2 + b^2 \): \[ a^2 + b^2 = 100 + 256 = 356 \]

    Now compare \( a^2 + b^2 \) with \( c^2 \): \[ 356 > 239 \]

    Since \( a^2 + b^2 > c^2 \), the triangle is classified as acute.

So the answer is: These side lengths form an acute triangle.