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 formula come from? One method of obtaining this ...

I write about mathematics and its applications The area and perimeter ratios ... the arc length of the upper half of the circle x² + y² = 1, the formula for which is (Funny aside: when I ...

Finding the area of a circle is easy with pizza and infinity. One of the oldest calculus problems, finding the area of a circle, can be visualized using a pizza. By dividing it up into ever ...

But unless you’ve really dug into it, you may only know the formula the way a school kid knows how to find the area of a circle. You have to have a bit of higher math to figure out why the ...

This means that, using Pythagoras’ theorem, the equation of a circle with radius r and centre (0, 0) is given by the formula \(x^2 + y^2 = r^2\). Find the equation of a circle with radius 3 ...

The tangent is perpendicular to the radius which joins the centre of the circle to the point P. As the tangent is a straight line, the equation of the tangent will be of the form \(y = mx + c\).

We need the areas of the triangles in column D from D3 to D11. The area of a circle is 3.14*(radius*radius). To create the formula in Excel, I could suggest the exponential function however ...