10-1 Angles Indicator: G2: Determine properties of 2- dimensional figures

Angle: Two rays with a common end point Degree: units used to measure the size of an angle (1 degree is 1/360 of a circle) Degrees are measured using a protractor

T O M What are the rays that make up this angles? OT & OM 4

How can you name this angle? S U E Vertex in middle and letters from each side Vertex Only Use a Number 2

Types of Angles Right Angle = 90 º Square in corner always means right angle. Straight Angle =180

Acute Angle 0 < x< 90 Obtuse Angle 90 < y < 180 X Y

Steps to draw an angle: 1.Draw a Ray 2.Place the center of the protractor on the endpoint and align the ray at 0 on the protractor 3.Count up by 10’s, then by ones until you get the desired measure and make a dot beside the marking 4.Draw a ray from the common endpoint through the point Try it: Make 75 º angle and name it <RST

To show the measure of an angle use the following notation: m<RST = 75° Read: the measure of angle RST is 75 degrees Adjacent Angles: Angles that share a common side and endpoint. AdjacentNon-adjacent

1)Name an obtuse angle 2)Name an acute angle 3)Name a pair of adjacent angles 4)Name a pair of non-adjacent angles 5)What is the measure of <ABD, <ABC (use correct notation) 30 A C B D

Homework 10-1 pages from packet– –Not the LAB PAGES…