Review question

# Given two tangents to a circle, can we find these lengths? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R9792

## Suggestion

In the diagram, $OA$ and $OB$ are tangents to the circle, centre $C$ and radius $\quantity{4.5}{in.}$ . The lines $OA$, $OB$ are inclined at $55^\circ$ and $25^\circ$ respectively to the straight line $XOY$.

Calculate

1. the angle $COY$;

What does the line $OC$ do to the angle $AOB$? Can you prove this? Which properties of tangents to a circle do you know?

1. the distance of $C$ from the line $XOY$.

Could we draw in the line we need on our diagram? What can we say now?