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

To find the largest angle in a triangle with angle measures \((x−20)^\circ\), \((3x+3)^\circ\), and \((2x−7)^\circ\), we can start by using the Triangle Angle Sum Theorem, which states that the sum of the angles in a triangle is \(180^\circ\).

First, we set up the equation:

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

Now, simplify the left side:

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

Combine like terms:

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

\[ 6x - 24 = 180 \]

Now, solve for \(x\):

  1. Add \(24\) to both sides: \[ 6x = 204 \]

  2. Divide by \(6\): \[ x = 34 \]

Now we can find the measures of each angle:

  1. For \((x - 20)^\circ\): \[ x - 20 = 34 - 20 = 14^\circ \]

  2. For \((3x + 3)^\circ\): \[ 3x + 3 = 3(34) + 3 = 102 + 3 = 105^\circ \]

  3. For \((2x - 7)^\circ\): \[ 2x - 7 = 2(34) - 7 = 68 - 7 = 61^\circ \]

The angles are \(14^\circ\), \(105^\circ\), and \(61^\circ\). Thus, the largest angle is:

\[ \boxed{105^\circ} \]