# Tangents on a circle

- Author:
- amyob88

## Move the points A, B, C and D around the screen. Notice what happens to the angles and lengths as this happens.

## Question 1

Consider the statement 'a tangent is a line that crosses a circle', is this... ?

## Question 2

A tangent is a line that touches a circle at one point

## Question 3

In the diagram, what is the relationship between the two line segments [BC] and [BD]?

## Question 4

In the diagram, what is the relationship between the angles ACB and ADC?

## Question 5

Under what condition are [BC] and [BD] equal?

## Question 6

Under what condition is angle BCD 90 degrees?

## Question 7

In the diagram, what shape(s) can the points A, C, B and D make?

## Question 8

What can be said about the points A, B and C?