Answer:
67.5 degrees
Explanation:
The sum of measures of angles around a circle is 360°. The little square in the corner of the one angle indicates that is a right angle, 90°. So you have ...
x + 3x + 90 = 360
4x = 270 . . . . . . . . . subtract 90, collect terms
x = 67.5 . . . . . . . . . divide by 4
The value of x is 67.5 degrees.
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If x is in radians, then it is 3π/8 radians.