Circles Equation Radian to Degree

In a circle with a radius of 2 in., an arc is 3 in. What is the central angle, in radians, that corresponds to this arc? What is the measure of the central angle to the nearest tenth of a degree?

• 3π radians; 85.9°

• 3π radians; 38.2°

• 1.5 radians; 85.9°

• 1.5 radians; 38.2°

Is the following equation an equation of a circle? If so, write in standard form. If not, explain why not.

• Yes; (x − 2)² + (y − 0)² = 15

• Yes; (x − 2)² + (y − 0)² = 11

• No; it is not an equation of a circle because the 4x term is not squared.

• No; it is not an equation of a circle because it is not possible to tell what the center of the circle would be.

• 30

• 330

• 360

•  300

Mathematical Equivalence

ON

How many radians does a circle have?

•   360 degrees

• 2pi radians

• pi radians

• ^{2 radians}

What is the equation of the circle shown in the graph?

Mathematical Equivalence

ON

Convert π radians to degrees.

• 90⁰

• 180⁰

• 360⁰

• 60⁰

• 60⁰

• 30⁰

• 90⁰

• 45⁰

Convert 4π/ 3 radians in degrees

• 120

• 240

• 210

• 270

Convert 7π/ 6 radians into degrees

• 225

• 210

• 270

• 240