Unit 6: periodic functions and trigonometry lesson 2: angles and the unit circle 1. find the measure of the angle. a. 145 b. 120 c. 90 d. 215 2. what is the measure of the angle in standard position? a. 30 b. 330 c. -60 d. -30 3. find the measure of an angle between 0 and 360 coterminal with an angle of -110 in standard position. a. 250 b. 20 c. 110 d. 70 4. find the cosine and sine of 210. round your answers to the nearest hundredth if necessary. a. -1, 0 b. -0.5, -0.87 c. -0.55, -0.95 d. -0.87, -0.5 5. find the exact value of sin 120. a. (*sqrt* 3)/2 b. -(*sqrt* 3)/2 c. 1/2 d. -1/2 ! i think #1 is a but that's all i

QUESTION 1

For this first question, we need to measure the angle from the positive x-axis up to the terminal side, which is in the second quadrant.

The measure of the angle




The correct answer is A.

QUESTION 2

First let us find the acute angle in the fourth quadrant.

This is given by


This implies that,






The angle in standard position



We measure from the positive x-axis in the anticlockwise direction.

The correct answer is B.

QUESTION 3

Coterminal angles are angles in standard position that have the same terminal side.

To find angles that are coterminal with


We either add or subtract 360°.

Since we want the to be between 0° and 360°, we have to add 360° to get,



The correct answer is A.

QUESTION 4

The acute angle that


makes with the x-axis is 30°.

Since 210 is in the third quadrant, both the sine and cosine ratio are negative.

This implies that,





Using the special angles,





Or





The correct answer is D.

QUESTION 5

The acute angle that 120° makes with the x-axis is 60°.

Since 120° is in the second quadrant, the sine ratio is positive.

This implies that,



Using special angles, the exact value is,



The correct answer is A.