How can I remember the values of sin60, sin30 sin45 e.t.c in my exams?

Firstly, you have to remember the equations for finding the sine, cosine and tangent of an angle. A good way of remembering this is to draw out the SOHCAHTOA triangles.To find the sin,cos and tan of 60 and 30 degrees, you need to draw an equilateral triangle of lengths 2 and split it down the middle, giving you a triangle with a hypotenuse of 2, a base legnth of 1, a side length of root 3 (found using Pythagoras theroem) and 2 internal angles of 60 and 30 degrees. You can then use SOHCAHTOA to find the desired values. To find the sin, cos and tan of a 45 degree angle, you can draw a right angled isosceles triangle with 2 equal sides of 1 and a hypotenuse of 45 degrees ( found using pythagoras theorem) and 2 equal internal angles of 45 degrees. You can then use SOHCAHYTOA to find the desired values.( I'm going to use the whiteboard to draw diagrams so it's easier to understand).