1 4 Warmup Simplify each absolute value expression

1 -4 Warmup Simplify each absolute value expression. 1) – 6 2) 3. 5 3) 7 – 10 4) – 4 – 2 5) – 2 – (– 4) 6) – 3 + 12 Solve each equation. 7. x + 2 x – 6 = 6 8. 3 x + 9 + 5 x = 81 9. w – 2 = – 4 + 7 w

Lesson 1 -4: Measuring Segments & Angles Term: Own words: Definition: Coordinate The location of a point. Congruent Objects that are the same shape and size A point that divides a segment into two equal segments Formed by two rays or segments that share an endpoint Midpoint Angle Acute angle Right angle Obtuse angle Straight angle An angle whose measure is smaller than a “corner” An angle whose measure is a “corner” - 900 An angle whose measure is greater than a “corner” An angle whose measure is a straight line - 1800

Measures with segments: Distance between two points is the absolute value of the difference between their coordinates. A B -1 0 1 Distance from A to B is Both equal 9! or

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

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

• Segment Addition: “parts of a segment add to the whole” ______ + ______ = ______ Small segment Whole segment • Midpoint – Forms 2 congruent segments on a segment (Cuts it in These red marks half!) A M – Equations: ____ = _____ Small segment Other small segment ____ = ½ ● ____ Small segment Whole segment B indicate segments AM and BM are the same.

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

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

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

Types of angles • Acute – “small” – Measures 00 - 890 • Right – “right turn” – Measures 900 • Obtuse – “obese” – Measures 910 - 1790 • Straight – Measures 1800 This red box indicates a right angle of 90 degrees.

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

Assignment: Practice 1 -4