Convert each degree measure to radian measure as a multiple of π. Do not use a calculator. (a) 30° radians (b) −20° radians

Question

Convert each degree measure to radian measure as a multiple of π. Do not use a calculator.

(a)    30°

 

 radians

(b)    −20°

 

 radians

Answer 1

There is a formula for this conversion it says simply

radians = degrees x π/180

One can simply plug in the numbers and do the math by hand noting that 30° and - 20° degrees are even numbers and both factors of 180

30° in radians = 30°π/180°

The degrees cancels out to π/6

If a number is required then the division can be done long hand without a calculated as stated

Give it a try with the -20°