Circle Concepts

What is the formula to calculate the circumference of a circle?

• 2 * π * r

• π * r^2

• 2 * r

• 2 * π * d

If a central angle of a circle is 60 degrees, what is the measure of the corresponding arc?

• 30 degrees

• 90 degrees

• 60 degrees

• 120 degrees

In a circle, what is the relationship between the radius and a tangent line?

• Intersecting

• Curved

• Parallel

• Perpendicular

How many degrees are in a semicircle?

• 180 degrees

• 90 degrees

• 360 degrees

• 270 degrees

What is the measure of an inscribed angle that intercepts a 70-degree arc?

• 35 degrees

• 70 degrees

• 90 degrees

• 110 degrees

If two chords intersect in a circle, the product of the segments of one chord is equal to the product of the segments of the other chord. This is known as which theorem?

• Concentric Circles Theorem

• Tangent Chords Theorem

• Parallel Chords Theorem

• Intersecting Chords Theorem

What is the relationship between the diameter of a circle and its radius?

• The diameter of a circle is equal to 2 times the radius.

• The diameter is half the radius

• The diameter is equal to the circumference

• The diameter is three times the radius

If two circles are congruent, what can we say about their radii?

• Their radii are not equal.

• Their radii are different.

• Their radii are proportional.

• Their radii are equal.

What is the formula to calculate the area of a circle?

• A = 2πr

• A = r^2

• A = πr^2

• A = 0.5πr^2

If a circle is inscribed in a triangle, what is the relationship between the radius of the circle and the sides of the triangle?

• The radius of the inscribed circle is r = A / s, where r is the radius, A is the area of the triangle, and s is the semiperimeter of the triangle.

• The radius of the inscribed circle is proportional to the sum of the sides of the triangle.

• The radius of the inscribed circle is equal to the perimeter of the triangle.

• The radius of the inscribed circle is half the area of the triangle.