Triangle Angle Sum Theorem

Definition: The Triangle Angle Sum Theorem states that the measures of all the interior angles of a triangle must equal 180 degrees.

Example: Find the missing value z in the triangle.

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Solution: 

The Triangle Angle Sum Theorem states that the measures of all the interior angles of a triangle must equal 180 degrees.

Step 1: We know that 45+76+z= 180

Step 2: We solve for z which = 59 degrees

To double check your work, look at the angle: is it an acute angle? (and angle that is less than 90?) Yes it is! So this answer makes sense.

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