When calculating angles using a circle theorem, always state which theorem applies. It may not be possible to calculate the missing angle immediately. It may be necessary to calculate another angle ...

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 ...

A full turn around a point equals 360º. If a full turn equals 360º, then the sum of the angles around a point must also be 360º. When you calculate angles around a point, you can use this fact to find ...