Use special right triangles: 45°-45°-90° and 30°-60°-90°
Memorize exact trig values for common angles: 0°, 30°, 45°, 60°, 90°
Use the unit circle to read exact values of sine, cosine, and tangent
Apply reference angles to find values in any quadrant
Determine the sign of the trig function based on the quadrant
Use reciprocal identities for cosecant, secant, and cotangent
Use Pythagorean identities to find missing exact values
Use angle sum and difference identities for nonstandard angles
Use double-angle and half-angle identities when needed
Simplify radicals and fractions to exact form
Rationalize denominators if required
Check for undefined values such as tangent at 90° and cosine at 90° in reciprocal forms