Answer:
m∠C = 98°
Step 1: Derive an Equation
To solve this problem, we will use what is called the Exterior Angle Theorem. This states that in a triangle, the measure of an <u>exterior angle</u> is equal to the sum of the measures of its 2 corresponding <u>remote interior angles</u>.
- <u>Exterior angle</u> - an angle formed by the extension of 1 side of the triangle
- <u>Remote interior angles</u> - the 2 angles that don't share a vertex with the exterior angle
In this case, the exterior angle is ∠T (the obtuse one) and the remote interior angles are ∠C and ∠Y. Therefore, <u>m∠T = m∠C + m∠Y</u>.
Substituting the given measures into the equation, we get:
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Step 2: Solve the Equation
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(Combine like terms)
(Subtract 2 from both sides to isolate
)
(Divide both sides by 4 to get rid of
's coefficient)
Step 3: Answer the Question
We now know what
is. Therefore, m∠C =
.
To learn more about the Exterior Angle Theorem, check out the following questions: