Page 114 - Math Course 2 (Book 2)

Perpendicular and Angle Bisectors
Mo. 10

Lesson 1 circumcenter

The 3 perpendicular bisectors of the sides of a
triangle meet in one point called the circumcenter.

KEY CONCEPTS: Its is the center of the circumcircle, the circle
circumscribed about the triangle. The circumcenter
1. Identify and use perpendicular bisectors. can be found as the intersection of the perpendicular
2. Identify and use medians in triangles. bisectors.
3. Identify and use altitudes in triangles.
C

MO. 10 - L1a

Identify and Use 0
Perpendicular Bisector

A B
Vocabulary A-Z

Let us learn some vocabulary

A incenter
2
The three angle bisectors of a triangle meet in one
point called the incenter.

M M It is the center of the incircle, the circle inscribed in
3 1 the triangle.

O A

A M A
1 2 3

incenter

perpendicular bisector
The perpendicular bisectors of a triangle are lines C
passing through the midpoint of each side which B
are perpendicular to the given side.

The perpendicular bisectors of △ are formed by lines
M , M , M . B
1 2 3
concurrent lines
When three or more lines intersect at a common M C M A
point, the lines are called concurrent lines.
c r a
The current lines of the △ are M , M , M . l r
3
2
1
point of concurrency r
The point of intersection for concurrent lines is
called the point of concurrency. A M b C
B
The point of concurrency for concurrent lines
M , M , M . is 0
3
2
1
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