Question

Is there an easy way i can find the related acute angle(reference angle) when give any degree? If not then can u tell me a method that is proper so that i can do good on reference angle

Answer 1

The method I teach is to draw the angle in standard position and the figure out how big the positive angle between the terminal side and the horizontal is.

I'm not sure what would be easier, but here's a numerical method. (One you could program a computer to do.)

For angle `A` given in degrees, If `A >= 360`, find `A_1 = A-360`

If `A_1 >= 360`, find `A_2 = A_1 - 360`

Continue until you get an angle `A_n < 360`

Call the reference angle `R`. and apply the four part rule:

If `0 <= A_n <= 90`, then `R = A_n`
If `90 < A_n <= 180`, then `R = 180 - A_n`
If `180 < A_n <= 270`, then `R = A_n - 180`
If `270 < A_n < 360`, then `R = 360 - A_n`

Not everyone will find this easier, but it does not require drawing a picture of the angle.