Find the radius of a circle inscribed in a 9‐12‐15 triangle.
15
9
r
r
r
12
.
Warm­up 10.4 ext
ABCD is tangent to the O.
AB = 10
AD = 15
BC = 18.
A
D
Find CD.
B
C
To tangent segments drawn from the same point are congruent.
walk around tangents
Circles A, B, and C are tangent. Find each radius if
AB = 15
BC = 17
AC = 12
B
A
C
walk around radii
more walk arounds #1
Circles A, B, and C are tangent. Find each radius if
AB = 8
BC = 13
AC = 11
8
A
B
x
13
11
C
walk around radii
.
Common external tangent ‐ Tangent OO's.
Ex: The two circles are externally tangent, Circle O has radius 9, circle P has radius 4.
Find the length of the common external tangent.
A radius drawn to a tangent is perpendicular at the point of tangency
.
.
comm ext tan
Mar 13­1:22 PM