Download Segments in Circles: Secants and Tangents

DO NOW: 3/9
Find the measure of x.
Segments in
Circles: Secants
and Tangents
Agenda
1. Do Now
2. Geogebra Investigation
3. Tangent Segment
Derivation
4. Independent
Practice/Debrief
Complete Part 1 and 2
We will use the chart below to record class measures and come up with
equations (questions #3 and 4)
Complete Part 3 independently, and compare to answer questions #3
and 4
Do Now 3/10:
Find the measure of x.
Segments in
Circles:
Practice
Agenda
1. Do Now
2. Segments in Circles
Equations
3. Segment in Circles Carousel
4. Exit Ticket
Chord Lengths (chord segment 1)x(chord segment 1) = (chord segment 2)x(chord segment 2)
Secant Lengths (whole secant 1)x(external secant 1) = (whole secant 2)x(external secant 2)
Tangent/Secant Lengths (whole secant 1)x(external secant 1) = (tangent)x(tangent)
1. Label each diagram with points
and additional information
(segment additon, etc.)
2. Write appropriate equation
based on types of segments in
circles.
3. Solve equation and check
answer.
Secant
Segments in
Circles:
Special Case
Agenda
1. Do Now
2. Secant Segments with
Quadratics
3. Solving Quadratics by
Factoring
4. Independent
Practice/Debrief
Do Now 3/11:
Find the measure of x.
When the external secant segment is unknown (a
variable) it is likely that we will end up with an equation
in the form of a quadratic.
(a)x2 + (b)x + (c) = 0
One way to solve these equations is by factoring.
1. Put into standard (a)x2 + (b)x + (c) = 0 form.
2. Identify factors of the (c) term.
3. Look for factors that also combine to equal the b term.
4. Set up two sets of parentheses (
front of each.
)(
) and put the factor of your (a) term in the
5. Put the two factors from step 3 in the end of each parentheses.
6. How to determine signs:
A. If (c) is positive, the signs in both parentheses are the same; match them with
the sign of (b)
B. If (c) is negative, the signs in both parentheses are different; match the sign
of the bigger factor with the sign of (b)
Well that was a fun trip down Algebra Memory
Lane! …Now back to Geometry and Circles.
How does this apply to the problem we saw
earlier?
Do Now 3/12:
Find the measure of x.
Segments in
Circles
Agenda
1. Do Now
2. Quiz: Segments in Circles
3. Embedded Assessment
4. Debrief
Happy (Day
Before) Pi Day!
3/14/15 @
9:26:53
Agenda
1. Embedded Assessment
Questions (#1)
2. Calculate
Circumference/Diameter of Pi
3. Find Area/Eat circular foods
4. Pi paper chain
Do Now 3/13:
𝜋≈
1. The circular track is tangent to each side of Quad ABCD A
and all of the angles in Quad ABCD are right angles. W, X,
Y, and Z are the points of tangency. Find each of the
following.
a. m𝑍𝑊
b. m𝑊𝑋𝑍
ITEM
CIRCUMFERENCE (C) DIAMETER (d)
RATIO (C/d)