The radius of a circle or a sphere is the distance between the center and the edge. The radius can be used to calculate a circle's diameter, area and circumference. Likewise, a sphere's volume is ...
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 you ...
You may be asked to show that two circles are touching, and say whether they're touching internally or externally. To do this, you need to work out the radius and the centre of each circle. If the sum ...