1-4 Warmup Simplify each absolute value expression. 1) –6 2) 3.5 3) 7 – 10 4) –4 – 2 5) –2 – (–4) 6) – Solve each equation. 7. x + 2x – 6 = x x = w – 2 = –4 + 7w

Lesson 1-4: Measuring Segments & Angles Term:Definition: Coordinate Congruent Segment Midpoint The location of a point. Objects that are the same shape and size A part of a line from one point to another A point that divides a segment into two equal segments

Measures with segments: Distance between two points is the absolute value of the difference between their coordinates. 01 AB Distance from A to B is or Both equal 9!

Example 3-1a Use the number line to find QR. The coordinates of Q and R are –6 and –3. Answer: 3 Distance Formula Simplify.

(cont’d) Symbol: AB means the segment: AB (without symbol) means the length Congruent segments –When 2 segments are the same length, we write… A B C D or

Segment Addition: “parts of a segment add to the whole” ___________ + ___________ = ____________ Midpoint –Forms 2 congruent segments on a segment (Cuts it in half!) –Equations: ________ = _________ ________ = ½ ● ________ AMB These red marks indicate segments AM and BM are the same. Small segment Whole segment Other small segment Small segment Whole segment

Example 3-5e Answer: D Multiple-Choice Test Item What is the measure of if B is the midpoint of ? A 1B 3C 5D 10

Angle Acute angle Right angle Obtuse angle Straight angle Term:Definition: Formed by two rays or segments that share an endpoint An angle whose measure is smaller than a “corner” An angle whose measure is a “corner” An angle whose measure is greater than a “corner” An angle whose measure is a straight line

Parts: Sides: rays BA and BC Vertex: point B Naming: 3 letters (all angles): 1 letter: 1 number: Angles B A C 1 or Only when there is exactly 1 angle at the vertex! sides vertex Tracing these letters makes the angle.

Example 4-1d a. Name all angles that have X as a vertex. b. Name the sides of  3. c. Write another name for  3. Answer:  1,  2,  3, and  RXB or  RXN Answer:  AXB,  AXN,  NXA,  BXA Answer:

Types of angles Acute – “small” –Measures Right – “right turn” –Measures 90 0 Obtuse – “obese” –Measures Straight –Measures This red box indicates a right angle of 90 degrees.

Example ;. Find 1 2 A B C We can write an equation by thinking: small + small = whole

Assignment: Practice 1-4