Circles Test Review

Front

What is a tangent to a circle?

Back

A tangent to a circle is a straight line that touches the circle at exactly one point, known as the point of tangency.

Front

What is the relationship between the angles formed by a tangent and a chord through the point of tangency?

Back

The angle formed between a tangent and a chord through the point of tangency is equal to the angle subtended by the chord in the opposite arc.

Front

How do you calculate the length of an arc in a circle?

Back

The length of an arc can be calculated using the formula: \( L = \frac{\theta}{360} \times 2\pi r \), where \( \theta \) is the central angle in degrees and \( r \) is the radius.

Front

What is the formula for the area of a sector of a circle?

Back

The area of a sector can be calculated using the formula: \( A = \frac{\theta}{360} \times \pi r^2 \), where \( \theta \) is the central angle in degrees and \( r \) is the radius.

Front

What is the measure of a full circle in degrees?

Back

A full circle measures 360 degrees.

Front

If the radius of a circle is doubled, how does the area change?

Back

If the radius is doubled, the area of the circle increases by a factor of four, since area is proportional to the square of the radius.

Front

What is the relationship between the central angle and the arc length in a circle?

Back

The arc length is directly proportional to the central angle; as the angle increases, the arc length increases.

Front

What is the formula for the circumference of a circle?

Back

The circumference of a circle can be calculated using the formula: \( C = 2\pi r \), where \( r \) is the radius.

Front

What is the definition of a chord in a circle?

Back

A chord is a line segment whose endpoints lie on the circle.

Front

What is the relationship between the angles subtended by the same arc at the circumference of a circle?

Back

The angles subtended by the same arc at the circumference of a circle are equal.