What is a tangent?

• A tangent to a circle is a straight line outside of the circle that touches its circumference only once

• Tangents are the easiest thing to spot quickly in a circle theorem question as they lie outside of the circle and stand out clearly

the tangent does not go in or out I just touches the circumference and because of this we get some properties just like a parallel line

Make sure that the line the tangent meets the radius

This circle theorem states that a radius and a tangent meet at 90°

• Perpendicular just means at right angles

When using this theorem in an exam you must use the keywords 

• A radius and a tangent meet at right angles

basically, for our igcse exam write this ⇬

What else should I know about tangents?

• Although it is not strictly a circle theorem the following is a very important fact for solving some problems

• Two tangents from a circle to the same point outside of a circle are equal

• This means that a kite can be formed by two tangents meeting a circle

  • Remember that a kite is essentially two congruent triangles about its main diagonal

  • The kite will have two right angles

the image that i am going to give is very important because i see this in paper everytime so plz remember this

an example for this thing:-