National 5 Using the sine and cosine rules to find a side or angle in a triangle How to know which formula to use The sine rule can be used to find an angle from 3 sides and an angle, or a side ...

Two High Schoolers Found an ‘Impossible’ Proof for a 2,000-Year-Old Math Rule—Then, They Discovered Nine More Ne’Kiya Jackson and Calcea Johnson of Louisiana published a new study proving ...