I'm reading Randall Munroe's book How To: Absurd Scientific Advice for Common Real-World Problems. I probably don't have to tell you this, but it's awesome (as is everything from Randall Munroe, the ...

👉 Learn how to solve equations using half-angle identities. To do this we will replace every trig function with half angles ...

Trigonometry close trigonometryThe study of sides and angles in triangles. can be used to find a missing angle in a right-angled triangle when two sides are known. An understanding of the three ...

It is important to remember other angles rules, such as angles on a straight line add up to 180°, and to recognise angles in parallel lines. Make sure you are confident in applying Pythagoras’ theorem ...