10.1 Lines and Segments that Intersect Circles with answersChapter
10 Circles 10.1 Lines That
Intersect Circles
line that intersects a circle
at two points.
a line that intersects
the circle at exactly one point.
– segment that has
it’s endpoints on the circle.
a chord that
contains the center of the circle.
– segment that has
one endpoint at the center of
the circle and the other
endpoint on the circle.
Segments of a Circle
E
A
G
Radius
Diameter
Chord
Tangent
Secant
Center the point in the middle of the
circle. Midpoint of the diameter and
endpoint of a radius in the circle.
Drag the word to the correct location on the diagram.
Center
the exact point is called the point of tangencypoint of tangency
Center Radius
1
2
3
4
5
1
2
3
4
5
diameter
chord
tangent
radius
secant
P
T
S
Is ST tangent to P?
In the diagram, point P is a point of
tangency. Find the radius r of O.
O
QP
r
r
36
24
50 ft
Hint: check answers by moving circles.
Use your knowledge about tangents to solve for EF and QS.
10.1 Lines and Segments that Intersect Circles with answers
Properties of Radii and Chords
2. If a diameter is 50 units long and a chord is 30 units long,
find the distance between the 2 segments.
1. Find CD.
C
A
B
Justin's bike has wheels with a 27 in. diameter.
a. What are AC and AD if DB is 7 in.? 13.5 in. 6.5 in.
b. What is CD to the nearest tenth of an inch? 11.8 in.
c. What is CE, the length of the top of the bike stand? 23.7 in.
Warm up DAY TWO 10.1
10.1 Lines and Segments that Intersect Circles with answers
Wikki Stick Intro Activity
Ch. 10 Circles: 10.1 Lines that intersect Circles
Grab wiki sticks bag and the
communicators. Follow the directions and
answer the questions in your notes.
10.1 Lines and Segments that Intersect Circles with answers
HW for 10.1
pg. 534: 5 9(o), 19 25 (o), 29 33
(o), 49, 50
Attachments
Circle Intro Activity with WIKKI STICKS 2012.docx
Circle Intro Activity
1. Create a DIAMETER of the circle using a blue string.
2. Create a RADIUS of the circle using a yellow string.
3. Create a SECANT of the circle using an orange string.
4. Create a TANGENT of the circle using a green string that touches
the RADIUS. Is the TANGENT parallel, perpendicular, or neither to
the RADIUS?
5. Using purple strings, create TWO CHORDS of the circle, so that
the DIAMETER and BOTH CHORDS make a triangle. Is the triangle
acute, right, or obtuse?
6. What is the circumference of your circle? (Use a ruler to get
the diameter.)
7. What is the area of your circle?
8. What is the area of the part of the circle that lies above the
DIAMETER? What is the area of the part that lies below the
DIAMETER?
SMART Notebook
Circle Intro Activity using Wikki sticks, ruler, and
protractor.
1. Create a DIAMETER of the circle using a blue string. How many
times does the diameter fit around the circle’s edge?
2. Create a RADIUS of the circle using a yellow string. What is the
relationship between this and the diameter?
3. Create a SECANT of the circle using an orange string. How does
this differ from the diameter and radius?
4. Create a TANGENT of the circle using a green string that touches
the RADIUS. Is the TANGENT parallel, perpendicular, or neither to
the RADIUS?
5. Using purple and pink strings create TWO CHORDS of the circle,
so that the DIAMETER and BOTH CHORDS make a triangle. Is the
triangle acute, right, or obtuse? What is the longest chord in a
circle?
6. What is the circumference of your circle?
7. What is the area of your circle? What is the ratio of the area
above the diameter to the area whole circle?
8. A central angle is formed by two radii. Use the marker to draw
an example of this angle on your circle then find the measure of
the central angle in degrees using your protractor. What percentage
of the circle does this angle represent?
Circle Intro Activity using Wikki sticks, ruler, and
protractor.
1. Create a DIAMETER of the circle using a blue string. How many
times does the diameter fit around the circle’s edge?
2. Create a RADIUS of the circle using a yellow string. What is the
relationship between this and the diameter?
3. Create a SECANT of the circle using an orange string. How does
this differ from the diameter and radius?
4. Create a TANGENT of the circle using a green string that touches
the RADIUS. Is the TANGENT parallel, perpendicular, or neither to
the RADIUS?
5. Using purple and pink strings create TWO CHORDS of the circle,
so that the DIAMETER and BOTH CHORDS make a triangle. Is the
triangle acute, right, or obtuse? What is the longest chord in a
circle?
6. What is the circumference of your circle?
7. What is the area of your circle? What is the ratio of the area
above the diameter to the area whole circle?
8. A central angle is formed by two radii. Use the marker to draw
an example of this angle on your circle then find the measure of
the central angle in degrees using your protractor. What percentage
of the circle does this angle represent?
SMART Notebook
Attachments Page 1