First, let's create a circle:
Then, let's explain what is a secant line and tangent line:
A)
A secant line is a line that intersects the circle in two points, and a tangent line is a line that intersects the circle in just one point:
B)
An inscribed angle is an angle that has the vertex as one point on the circle, and a central angle is an angle that has the vertex as the center of the circle: