To find the equation of a circle when you know the radius and centre, use the formula \({(x - a)^2} + {(y - b)^2} = {r^2}\), where \((a,b)\) represents the centre of the circle, and \(r\) is the ...

because there are 360 degrees in a circle. If 25 out of 100 students travel to school by car, the angle is worked out using the calculation: (25 ÷ 100) × 360 = 90 degrees. Scatter graphs show ...