Measuring Lengths

1
Measuring Lengths Angles
2
Measure of Segment AB

• The length of AB is the absolute value of a-b.
• a-b or b-a

A
B

a
b
3
Congruence

• Objects that are congruent have the same measure

4
Segment Addition Postulate

• If point R is between points P and Q,
• then
• RP PQ PQ

P
R
Q

5
Angle Measure (using a protractor)

• Line up site with vertex
• Line up one side with 0
• Read angle measure using other side

6
Angle Addition Postulate

• If point S is in the interior of ltPQR,
• then
• mltPQS mltSQR mltPQR

P

S

Q
R

7
Special Angle Sums
If the sum of the measures of two angle

• 90 gt Complementary
• 180 gt Supplementary