Circles

A circle is a perfect round shape where every point on the edge is the same distance from the centre. The main parts you must know are the radius (line from centre to edge), diameter (line across through the centre), circumference (the outer edge), and chord (any line joining two points on the circle).

Understanding circle properties helps you solve drawing problems. The diameter is always twice the radius, and opposite angles in a cyclic quadrilateral always add up to 180 degrees. When constructing circles, you'll use a compass to maintain equal radius measurements.

Think of Lagos Island's roundabout at Ikoyi—it's circular, and the radius determines how far vehicles travel from the centre point. In your WAEC drawings, you'll construct tangent lines, divide circles into equal parts, and draw arcs accurately.