An angle measures radians. A circle with a radius 2.8 cm long is centered at the angle's vertex. The terminal point is highlighted in purple. An angle is drawn within a circle centered at its vertex. The radius length of 2.8 centimeters is marked in green, and the terminal point is marked in violet. A horizontal solid blue vector indicates that the terminal point's distance to the right of the vertical diameter is 2.58 centimeters. A vertical solid orange vector indicates that the terminal point's distance above the horizontal diameter is 1.09 centimeters. The terminal point's horizontal distance to the right of the circle's center is times as large as the circle's radius, and therefore: cos ( ) = The terminal point's vertical distance above the circle's center is times as large as the circle's radius, and therefore: sin ( ) =