This video tutorial introduces the concept of circles, defining key terms such as radius, chord, and diameter. It explains the properties of secants and tangents, including common tangents between circles. The video covers theorems related to tangents, demonstrating their application through examples and problem-solving exercises.

What is a circle defined as in geometry?

• A shape with four equal sides

• A set of points equidistant from a center point

• A polygon with three sides

• A line segment with two endpoints

Which of the following is a segment with endpoints on the circle?

• Radius

• Chord

• Diameter

• Secant

What is a diameter in relation to a circle?

• A segment with one endpoint at the center

• A segment that passes through the center and has endpoints on the circle

• A line that intersects the circle at two points

• A line that touches the circle at one point

How is a secant different from a tangent?

• A secant is a line that does not touch the circle

• A secant intersects the circle at two points

• A secant is a segment with endpoints on the circle

• A secant intersects the circle at one point

What is a tangent in relation to a circle?

• A line that touches the circle at exactly one point

• A line that does not intersect the circle

• A line that intersects the circle at two points

• A segment with both endpoints on the circle

What is a common tangent?

• A line that is tangent to one circle at two points

• A line that does not touch any circle

• A line that intersects two circles at two points each

• A line that is tangent to two circles at one point each

How many common tangents exist when two circles do not intersect?

• Three

• Two

• Four

• None

What condition must be met for a line to be tangent to a circle?

• The line must intersect the circle at two points

• The line must be perpendicular to a radius at the circle's edge

• The line must be parallel to a radius

• The line must be a secant

What does the theorem about tangent segments from a common external point state?

• They are always different in length

• They are congruent

• They intersect at the center of the circle

• They form a right angle with the radius

In a right triangle formed by a tangent, what role does the tangent play?

• It is the height

• It is one of the legs

• It is the hypotenuse

• It is the base