angle ratios in a triangle

1. Triangle Ratio Example

2. The measures of the angles in a triangle are in
the extended ratio of 2:2:5. Find the measures
of the angles.
• Draw a Picture, label the angles
5x
2x 2x

3. Set up your equation
• The angles in a triangle always add to 180 so:
2x +2x + 5x = 180

4. Solve
• 2x +2x +5x =180
• 9x=180
• x=20

5. Substitute
• The problem wants the angles, not x. Plug in x=20 into your angles.
5x=5(20)=100
2x=2(20)=40 2x=2(20)=40

6. Answer
• Your angle measures are 100°, 40°, and 40°