A tangent to a circle at point P is a straight line that touches the circle at P. The tangent is perpendicular to the radius which joins the centre of the circle to the point P. As the tangent is a ...

So you have a circle. What is the area of that circle? Surely everyone remembers that the area of a circle is: Where Pi (π) is of course the number and r is the radius of the circle. Where does this ...

Everything in physics is described by an equation. Equations can describe the shape of lines, curves, surfaces, and just about any object you can think of. In fact, you’d be hard-pressed to think of ...