Solving Circle And Tangent Questions (gcse Maths)

1. Revising your circle theorem rules are crucial - practice these questions in isolation to really reinforce your knowledge on circle theorems.

2. Remembering the rules of straight lines - two straight lines that are perpendicular to each other will have gradients that are the negative reciprocal of each other. So if one line has a gradient of 2, the perpendicular line to this will have a gradient of -1/2.Now we apply this to circles and tangents: the radius of a circle at a particular point will be perpendicular to the tangent at that same particular point - and this helps us massively when we`re trying to work out the equation of the line. Once we have the gradient, we just have to substitute values to find the `+ c` value!

3. Remembering two important equations:

- y = mx + c: this is the most commonly used equation

- y -y1 = m(x - x1) : not many people use this equation however it proves so useful and is actually arguably more useful than the other equation.

4. If an angle is given, that question is probably trying to get you to use trigonometry. If so, try and construct a right angled triangle where possible so it is a simply soh-cah-toa to find the angle or the side you are looking for!