Exterior Angle of a Triangle

The video tutorial explains the concept of exterior angles in a triangle, emphasizing that the exterior angle equals the sum of the two non-adjacent interior angles. It covers solving equations involving angles, using the properties that the sum of interior angles in a triangle is 180 degrees and that angles on a straight line sum to 180 degrees. The tutorial provides step-by-step guidance on solving these equations and highlights common pitfalls in standardized tests, emphasizing the importance of understanding the question requirements.

What is an exterior angle of a triangle equal to?

• Twice the largest interior angle

• The difference between two interior angles

• The sum of the two non-adjacent interior angles

• The sum of all interior angles

If one interior angle of a triangle is 50 degrees, what is the measure of the exterior angle adjacent to it?

• 50 degrees

• 130 degrees

• 180 degrees

• 100 degrees

In solving for an unknown angle in a triangle, which property is used to relate the angles?

• Angles in a triangle sum to 360 degrees

• Exterior angle equals the sum of two adjacent angles

• Angles in a triangle sum to 180 degrees

• Exterior angle equals the sum of two non-adjacent interior angles

What is the first step in solving the equation 40 + X = 3X - 10?

• Multiply both sides by 3

• Add 10 to both sides

• Subtract X from both sides

• Divide both sides by 2

After solving for X in the equation 40 + X = 3X - 10, what should you do if the problem asks for the measure of a specific angle?

• Add 10 to X

• Use X to calculate the specific angle

• Stop, as you have found X

• Multiply X by 2