degrees * pi.180 = radians.
Do not use the value of pi. Use "pi".
For example 30 degrees = 30*pi/180 = pi/6 radians.
pi/2 radians = pi/2 * 180/pi = 90 degrees.
Hope the solution helped. Sometimes you need more than a solution. Contact fcabanski@hotmail.com for online, private tutoring, or personalized problem solving (quick for groups of problems.)