Download Calculus Fall 2010 Lesson 01

1
Lesson Plan #003
Date: Tuesday September 11th, 2012
Class: Geometry
Topic: Definitions involving angles
Aim: What are some definitions involving angles?
Objectives:
1) Students will be able to state various angle properties.
NOTE: OBTAIN A COMPASS AND PROTRACTOR AND BRING IT WITH YOU TO CLASS EVERY DAY.
HW# 003:
Do Now:
PROCEDURE:
Write the Aim and Do Now
Get students working!
Take attendance
Go over the Do Now
Is this person hitting the ball at the correct angle? Hmm…, let’s first
discuss angles and their properties.
Definition: An angle is the set of points that is the union of two rays having
the same endpoint.
1
The two rays are called the sides of the angles, and their common endpoint is called the vertex of the angle. The sides of the angle
shown are BA and BC . The vertex is point B.
How can we name the angle to the right?
2
Name all the angles shown at right.
How do we determine how big is an angle?
What is a unit of measurement of an angle?
What can be used to measure an angle?
Angles can be classified according to their measures?
Definition: A right angle is an angle whose degree measure is 90o.
Definition: A straight angle is an angle whose degree measure is 180o.
Type of Angle
Description
Acute Angle
an angle that is less than 90°
Obtuse Angle
an angle that is greater than 90° but less than 180°
Reflex Angle
an angle that is greater than 180°
What is the definition of congruent angles?
Definition: Adjacent Angles are two angles in a plane that have a common vertex and a common side, but no common interior
points.
What is the definition of congruent angles?
3
Definition: A bisector of an angle is a ray whose endpoint is the vertex of the angle, and that divides the angle into two
congruent angles.
Given the diagram at right and
be made?
BD bisects  ABC , what statements of congruence can
What statements of equality can be made?
The above observation leads us to the postulate
4
5