the radius of the circle is perpendicular to line AB, line AB is tangent to the circle
Explanation:
A radius is a line drawn from the center of the circle to the circumference of the circle
A diagram to show the radius:
The radius of the circle and line AB form ⊥ (perpendicular lines)
Both form angle 90 degres
A tanglent is a line that touches the circle at one point.
Line AB touches the circle at a point (the point where the radius line touches the circle)
Tangent of a circle is alays perpendicular to the radius
So from the above, we can conclude:
Since the radius of the circle is perpendicular to line AB, line AB is tangent to the circle
