ACT Math : How to find a reference angle

Study concepts, example questions & explanations for ACT Math

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Example Questions

Example Question #51 : Trigonometry

What is the reference angle for ?

Possible Answers:

Correct answer:

Explanation:

A reference angle is the smallest possible angle between a given angle measurement and the x-axis.

In this case, our angle  lies in Quadrant III, so the angle is found by the formula .

  

Thus, the reference angle for  is .

Example Question #51 : Trigonometry

What is the reference angle for ?

Possible Answers:

Correct answer:

Explanation:

A reference angle is the smallest possible angle between a given angle measurement and the x-axis.

In this case, our angle  lies in Quadrant II, so we can find our reference angle using the formula

.

  

Thus, the reference angle for  is .

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