A sector is a fraction of a circle. The angle in the sector is a fraction of 360°. This sector has an angle of θ°. The fraction of the circle is \(\frac{θ}{360}\) The area of the sector will be ...

Forbes contributors publish independent expert analyses and insights. I write about mathematics and its applications The area and perimeter ratios are shown and as n ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Using cushions to build a fort, explore the concept of finding the largest area for a fixed perimeter.

The number pi (π) appears in the most unlikely places. It can be found in circles, of course—as well as in pendulums, springs and river bends. This everyday number is linked to transcendental ...