3.3 cpctc and circles objective: after studying this lesson you will be able to apply the principle...
DESCRIPTION
Point O is the center of the circle shown below. Definition of a circle:every point of the circle is the same distance from the center. O The center is not a part of the circle, just the outside or the “rim”. Circles are named by their centers. The circle above is named circle O orTRANSCRIPT
3.3 CPCTC and Circles3.3 CPCTC and Circles
Objective: After studying this lesson you will be able to apply the principle of CPCTC and recognize
some basic properties of circles.
AA
CCTT
CPCTCCPCTC
““CCorresponding orresponding PParts of arts of CCongruent ongruent TTriangles are riangles are CCongruent”ongruent”
OO
DDGG
Suppose that . Can we say that ?
After we have proven two triangles are congruent we will use
as a reason. Corresponding parts refer to the matching angles and sides in the respective triangles.
DOG CAT D C
Point O is the center of the circle shown below.
Definition of a circle: every point of the circle is the same distance from the center.
OO
The center is not a part of the circle, just the outside or the “rim”. Circles are named by their centers.The circle above is named circle O or O
PPAA
BBCC
Points A, B, and C lie on circle P. PA is called the radius
PA, PB, and PC are called radii.
Formulas to remember!2
2A rC r
Theorem: all radii are congruent
Given:
Prove: AB CD
Statement Reason
DD
BB
CC
AA
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
P PP
Given:
Prove:
is complementary to T MOT
MO PO
Statement Reason
1.
2.
3.
4.
5.
6.
7.
8.
1.
2.
3.
4.
5.
6.
7.
8.
O
RR
SS
TT
KKOO PP
MM is complementary to S POS
Summary:Summary:When is it appropriate to When is it appropriate to use CPCTC as a reason in use CPCTC as a reason in a proof?a proof?
Homework: worksheetHomework: worksheet