# Getting the sides of unit circle

Im very confused on how to get the sides of the unit circle. By that i mean like sin/cos of 0,90,180,360... I can get the others by this logic for example:

Image:

For example if it asks me

1. Sin 150: I would first see the quadrant.. Its Quadrant II so it means Sin is the only one positive... Ok so i know its positive, and next i would know that sin is always the hieght so according to that picture it is 1/2.. So i would know the sin of 150 is 1/2...

I can do that for every angle presented on the picture exept the 0,90,180,360... How do you possible calculate the sin/cos for the angles i just mentioned. Thankyou

• The only way out of it i can guess is memorizing the pattern....??? @LuizCordeiro – amanuel2 Feb 29 '16 at 22:39
• Im not memorizing all... Im just memorizing 0,90,180,360.... the others are easy to figure out.. And its just a pattern.. For cos in 0-360 it goes 1,0,-1,1 For sin 0,1,0,0 – amanuel2 Feb 29 '16 at 22:47

In the following triangles, use the Pythagorean theorem to find the missing lengths, then find the trigonometric ratios for $0,\pi/2, \pi/3,\pi/4,$ and $\pi/6$. Don't even bother memorizing, just draw the appropriate triangle.
• @Surb The degenerated triangle is for calculating $\sin 0$ and $\sin\pi/2$ ala opposite-adjacent-hypotenuse style. – John Joy Mar 1 '16 at 15:47