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The reference angle for an angle whose measure is -440° is _____.

User Najla
by
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2 Answers

6 votes

Answer:

The reference angle for an angle whose measure is -440° is 80°.

Explanation:

The cycles for angles range from the traditional 0° to 360° and subsequent 360° ranges befor and after this traditional intervals, also have the same properties.

So, the ranges that exist and correspond to the traditional 0° to 360° include

0° to 360°

360° to 720°

720° to 1080°

And in the negative direction, we have

-360° to 0°

-720° to -360°

We can see that -440 is in the range of

-720° to -360°

Using the traditional 0° to 360° to compare this range of -720° to -360°, let x represent the reference angle in the traditional range that we require.

-720° ------ 0°

-440° ------ x

-360° ------ 360°

Using interpolation,

[-440° - (-720°)]/[-360° - (-440°)] = (x - 0°)/(360° - x)

(280/80) = x/(360-x)

3.5 = x/(360-x)

3.5(360 - x) = x

1260° - 3.5x = x

4.5x = 1260°

x = (1260°/4.5) = 280°

But, the reference angle is the smallest angle that one can make from the terminal side of an angle (that is, where the angle ends) with the x-axis. It uses the x-axis as its frame of reference.

So, 280° is a fourth quadrant angle, whose equivalent in the first quadrant is 360° - 280° = 80°

Hope this Helps!!!

User Frank Farmer
by
4.6k points
3 votes

Answer:

The reference angle is the acute angle formed by the terminal side of an angle in standard position and the x-axis

Explanation:

-440° will be in the 1st quadrant

We solve by adding 360° to it till it becomes positive

-440°+360°= -80°

-80°+360°=280°

The equivalent value will become

360°-280°= 80°

User Kevin Craft
by
4.9k points