PSAT – QUESTION OF THE DAY

(B) 8

FINDING ANGLE MEASURES USING CLOCKS

SEGMENT AND ANGLE ADDITION

LENGTH OF A SEGMENTThe length of a segment can be found two

ways.1. Counting spaces2. Subtracting (We are finding distance so we

take the difference)Find the length of segment AB.

B – A = 4 – (-2) = 6

There is no such thing as a negative distance.

SEGMENT AND ANGLE ADDITION POSTULATES

The segment and angle addition postulates say that you can add two angles together to get a larger angle and two segments together to get a larger segment.

For Example: AB + BC = AC

How long is segment AC?15 units

CBA10 5

SEGMENT AND ANGLE ADDITION POSTULATES

<AOB = 43 and <BOC = 15What is the measure of <AOC?

<AOB + <BOC = <AOC 43 + 15 = <AOC

58 = <AOC

SEGMENT AND ANGLE ADDITION POSTULATES

XZ = 17 and YZ = 11What is the length of segment XY?

XY + YZ = XZXY + 11 = 17

XY = 6

SEGMENT AND ANGLE ADDITION POSTULATES

<ABC = 124. Find the measure of x.

Top < + Right < = Total <<ABD + <DBC = <ABC (3x+1) + (4x-3) = 124

7x – 2 = 124 7x = 126x = 18

MIDPOINTS A midpoint of a segment is a point that

divides a segment into two equal pieces. Small dash marks are used to show that the two halves are equal.

MIDPOINTSM is the midpoint of AB. AM = 3x-6 and MB = 5x-12. Find the measure of x.

3x – 6 = 5x – 126 = 2x3 = x

3x-65x-12

HOMEWORK

Geometry:Pg 29 (1,8-13,17,27-30,33,43,45,65,70)

Honors Geometry:Pg 29 (1,8-13,17,27-30,33,65,70,71,75-

78)

HONORS GEOMETRYIn Pairs, work on the following problems:

Pg 32 (75-78).

Please draw the picture and label it for each problem.