1. CIRCLE GEOMETRY
MathLinks 9 ~~~ chapter 10

2. 10.1 Exploring Angles in a Circle
Mark two points on the
bottom half of the circle.
Mark a point on the top half *
of the circle. *
Join each of the bottom dots
to the top dot.
Measure the inscribed angle.
Draw a second point on the
top half of the circle, and
repeat the process.
What do you notice about the measures of the two inscribed angles?

3. Construct an inscribed angle that
is subtended by a diameter.
*
Measure the inscribed angle.
What is the measure of any inscribed angle subtended by a diameter?

4. Draw an inscribed angle.
Draw a central angle subtended
by the same arc as your
inscribed angle. *
Measure the inscribed angle. *
Measure the central angle.
What is the relationship between the measures of an inscribed
angle and a central subtended by the same arc?

5. 10.1 Exploring Angles in a Circle
Notes . . . please copy.
When two inscribed x x
angles are
subtended by the
same arc, their
measures are equal.

6. When an inscribed angle is
subtended by a diameter,
its measure is always 90°.

7. When an inscribed
angle and a central x
angle are subtended by
the same arc, the 2x
measure of the central
angle is double the
measure of the
inscribed angle.

8. Add definitions for these terms to your notes.
Include a diagram for each.
ARC
CHORD
CENTRAL ANGLE
INSCRIBED ANGLE

9. Textbook assignment --- 10.1 “Practise”
#3
#4
#6#8
#10
#12#15
#20
challenge: #18 and/or #21