1. Day 2 Students will be able to convert between radians and degrees. Revolutions, Degrees, and Radians

2. Launch A radian is the measure of a central angle such that the arc (pie crust) is equal to the radius of the circle. Like when we cut the string to the length of the radius and wrapped it around the outside of the circle and marked the angle if formed. That angle was one radian. There are 2  radians and 360  degrees in the circumference of a circle. I know this because we wrapped a string the length of the radius around half of the circle a little more than 3 times, which we said was  times. So, the entire circle would be 2  times.

3. Launch – How do you convert 120  to radians? CyrelShai I know 360  = 2  radians. Since, 120  is 1/3 of 360 . So to keep the equation balanced, I will multiply both sides by 1/3. 360  = 2  radians. So to figure out 1 , I will divide both sides by 360 . So to find 120 , I will multiply both sides of the equation by 120.

4. Launch – Which method do you think is easiest? CyrelShai I know 360  = 2  radians. Since, 120  is 1/3 of 360 . So to keep the equation balanced, I will multiply both sides by 1/3. 360  = 2  radians. So to figure out 1 , I will divide both sides by 360 . So to find 120 , I will multiply both sides of the equation by 120.

5. Explore

6. How would you find the degrees for radians? Launch

7. Explore

8. Summary How do you converts between radians and degrees?

9. Exit Question To convert 315  to radians, I would ____________________________________________ ____________________________________________ ____________________________________________ ___________________________________________. To convert radians into degrees, I would ____________________________________________ ____________________________________________ ____________________________________________ ___________________________________________.