The circumference of a circle = \(\pi d\) or \(2\pi r\). Look at the sector of the circle shown below. To calculate the length of the arc, we need to know what fraction of the circle is shown.

This creates shapes like the deltoid, which is a roughly triangular shape that may remind you of your old Spirograph drawing toy. The deltoid can have a much smaller area than the circle that would ...

THIS work of Prof. Smith's has a “very practical purpose,” viz, “to present in simple and intelligible form a body of geometric doctrine, acquaintance with which may fairly be demanded of ...

A circle is a shape where every point at its edge is the same distance from the centre. A circular shape or object is one that is in the form of a circle. How many of these circular objects can ...

Dividers and compasses are drawing instruments that have been used since antiquity to measure distances, transfer lengths from one drawing to another, and draw circles. The Greek mathematician, Euclid ...

The diameter of the circle is given an arbitrary value of 1 ... which were unknown in Archimedes' day—Archimedes used geometry instead. For example, he knew the ratio between one line and ...