Want to calculate the radius of a circle from its area or perimeter? Here are the key formulas that no one explains clearly! #CircleRadius #MathTip #EasyGeometry McCarthy says Trump ‘having to ...

To work out the area of a circle: Find the value of the radius. If the diameter is given, this must be halved. Substitute the value of the radius into the formula for the area of a circle.

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 ...