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Mathematics>Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer.

If θ= 315°, what is the value of θ in radians?

A.5/4π
B.3/2π
C.5/3π
D.7/4π

答案和解析

答案：D

解析：

Choice D is correct.
Recall that there are 2π radians in one revolution of a circle. There are also 360° in one revolution of a circle.
This leads to the following conversion:
2π radians=360°
Dividing both sides by 360 gives 1°= π/180 radians. This factor can be used to convert°s to radians.
The conversion is performed below. 315° = 7/4π