SSAT Upper Level Math : How to find if acute / obtuse triangles are congruent

Study concepts, example questions & explanations for SSAT Upper Level Math

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Example Questions

Example Question #1 : Acute / Obtuse Triangles

If the vertex angle of an isosceles triangle is 30 degrees, what is the value of the angle that is exterior to one of the base angles?

Possible Answers:

\(\displaystyle 105^{\circ}\)

\(\displaystyle 75^{\circ}\)

\(\displaystyle 15^{\circ}\)

\(\displaystyle 150^{\circ}\)

\(\displaystyle 30^{\circ}\)

Correct answer:

\(\displaystyle 105^{\circ}\)

Explanation:

First, you subtract one angle so \(\displaystyle 180-30 = 150\). Because there are 2 base angles you divide that value by 2 to get 75 Degrees. The exterior angle and the base angle are supplementary angles so \(\displaystyle 180-75 = 105\).

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