Use the Triangle Angle Sum Theorem to find the largest angle in a triangle with angle measures of (x−20)°

, (3x+3)°
, and (2x−7)°
.(1 point)
°

1 answer

The Triangle Angle Sum Theorem states that the sum of the interior angles of a triangle is always 180 degrees.

For the triangle with angle measures \( (x - 20)^\circ \), \( (3x + 3)^\circ \), and \( (2x - 7)^\circ \), we set up the equation:

\[ (x - 20) + (3x + 3) + (2x - 7) = 180 \]

Now, combine like terms:

\[ x - 20 + 3x + 3 + 2x - 7 = 180 \]

This simplifies to:

\[ (1x + 3x + 2x) + (-20 + 3 - 7) = 180 \]

\[ 6x - 24 = 180 \]

Next, add 24 to both sides:

\[ 6x = 204 \]

Now divide by 6:

\[ x = 34 \]

Now we can find the measures of the angles:

  1. \( (x - 20)^\circ = (34 - 20)^\circ = 14^\circ \)
  2. \( (3x + 3)^\circ = (3 \cdot 34 + 3)^\circ = (102 + 3)^\circ = 105^\circ \)
  3. \( (2x - 7)^\circ = (2 \cdot 34 - 7)^\circ = (68 - 7)^\circ = 61^\circ \)

Now, we have the angle measures:

  • \( 14^\circ \)
  • \( 105^\circ \)
  • \( 61^\circ \)

The largest angle is \( 105^\circ \).

Thus, the largest angle in the triangle is:

\[ \boxed{105} \]