Could someone explain how they get the answer for this?
1 answer:
Answer:
40°
Step-by-step explanation:
The reference angle is the positive acute angle created by the terminal arm and the x-axis.
The highlighted red in the picture below shows what we're looking for.
The arm rotated 220° (but 'backwards' so the value given is negative).
|-220°| - 2(90°) <= Subtract two right angles for two quadrants
= 220° - 2(90°)
= 220° - 180°
= 40°
Therefore, the reference angle is 40°.
If you got 50°, you probably calculated the angle with the terminal arm and the y-axis. Remember to always use the nearest side of the x-axis!
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Answer:
30.7 km
Step-by-step explanation:
The distance between the two fires can be found using the Law of Cosines. For ΔABC in which sides 'a' and 'b' are given, along with angle C, the third side is ...
c = √(a² +b² -2ab·cos(C))
The angle measured between the two fires is ...
180° -(69° -35°) = 146°
and the distance is ...
c = √(11² +21² -2(11)(21)cos(146°)) ≈ √945.015
c ≈ 30.74
The straight-line distance between the two fires is about 30.7 km.
