**Question: **What names can be used to describe the straight line AB, the curved lines AB, and the straight line BC?

**Answer:**The straight line passing through A and B intersects the circumference twice and doesn’t pass through the centre, so it’s a **chord.** The straight line BC touches the circumference of the circle just once, so it’s a **tangent**. There are two curved lines joining A and B: the ‘big part’ of the circumference and the small part of the circumference. These are both **arcs**.