• Students' Heights      3 feet 11 inches 46 inches

4 feet 8 inches 48 inches   4 feet 2 inches  52 inches

Drew, Erin, Jamal, Kendra, Parker, and Sandy have lined up according to height so they can be placed on-stage for the spring concert. The shortest person is at the front of the line. Drew is behind Kendra. Erin is right behind Parker. Jamal is between Parker and Drew. Sandy is one inch shorter than Kendra. Kendra is second in line. What is each person's height in feet and inches? In what order are they standing in line?

Solution

• Height Student

• 3 feet 10 inches Sandy

• 3 feet 11 inches Kendra

• 4 feet Drew

• 4 feet 2 inches Jamal

• 4 feet 4 inches Parker

• 4 feet 8 inches Erin

Classifying and Measuring Angles

Lesson 10-1

Angles

• An angle is made up of 2 rays with a common end point.

• Angles are measured in units called degrees.

Vertex- the point where the 2 rays meet.

Naming AnglesC

B

A

2

You can use the symbol to name the angle.

ABC or CBA Always use the vertex as the middle letter.

B Use the vertex only

2 Use a number

Types of AnglesAcute Angle

Right Angle

Obtuse Angle Straight Angle

Measure less than 90Measure exactly 90

Measure between 90 and 180 Measure exactly 180

Find the measure of an angle

M

R

P

N

60

85

The outer scale goes from 0 to 180 from left to right.

The inner scale goes from 0 to 180 from right to left.

Protractor

How to measure an angle

Line up the vertex of the angle with the center of the protractor.

Lay one of the rays of the angle on the line passing through zero.

If the ray passes through this zero, use the outer scale.

If the ray passes through this zero, use the inner scale.

•Measure this angle from the inner scale. •This angle measures 75

•Measure this angle from the outer scale.•This angle measures 100

Draw an Angle that measures 60

First draw a ray.

Next lay the protractor on top of the ray with the end point at the center of the ray.

Draw an Angle that measures 60 Then draw the other ray passing it through this point.

Mark the point on the protractor that you want the other ray to pass through.

Draw an Angle that measures 60

Your Turn

• Measure the angles on your worksheet.

• Draw your own angle that measures 45

• Remember to line up the vertex with the center point.

• If you need to extend the ray so that it passes through the zero mark.

Don’t forget

• Complete lesson 10-1 # 1-14 all