Save guides, add subjects and pick up where you left off with your BBC account. To find the equation of a circle when you know the radius and centre, use the formula \({(x - a)^2} + {(y - b)^2} ...

It may also be helpful to understand π (pi) and the circumference of a circle. The formula for the area of the circle is 𝑨 = π𝒓². To work out the area of a circle: Find the value of the ...