Circles

Author:: Ryanne Hilliard

Topic:: Circle

Central Angles, Arcs, and Chords

Step 1

Use the LINE tool to construct a line through Center A and Point B.

Step 2

Construct a Point C on the circle using the POINT tool .

Step 3

Use the LINE tool to construct a line through Center A and Point C.

Step 4

Click the Point tool in the toolbar. Then use the INTERSECTION tool to construct Point D and Point E. (Point D should intersect line AB and the circle. Point E should intersect line AC and the circle.)

Step 5

Use the ANGLE MEASURE tool to create and measure angle BAC and angle DAE. *First select the point B, then center A, then select point C counterclockwise!* *First select the point D, then center A, then select point E counterclockwise!*

Step 6

Use the CIRCULAR ARC tool to create and measure Arc BC and Arc DE. *First select the center A, then select Points B and C counterclockwise!* *First select the center A, then select Points D and E counterclockwise!*

Step 7

Use the Algebra window to see the measures of Arc BC (labeled "d") and Arc DE (labeled "e").

Step 8

Use the SEGMENT tool to construct Chord "h" with endpoints B and C. Use the SEGMENT tool to construct Chord "i" with endpoints D and E.