∠ E C D = 122 ° \angle ECD=122\degree ∠ E C D = 1 2 2 ° and ∠ B C E = 36 ° \angle BCE=36\degree ∠ B C E = 3 6 ° . Find the measure of ∠ B C D \angle BCD ∠ B C D .

∠ B C D = 158 ° \angle BCD=158\degree ∠ B C D = 1 5 8 °

∠ B C D = 86 ° \angle BCD=86\degree ∠ B C D = 8 6 °

∠ B C D = 58 ° \angle BCD=58\degree ∠ B C D = 5 8 °

∠ B C D = 144 ° \angle BCD=144\degree ∠ B C D = 1 4 4 °

Angle Addition

Presentation

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Mathematics

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9th Grade

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Practice Problem

•

Medium

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CCSS

7.G.B.5, 4.MD.C.7

Standards-aligned

Rebecca Louvain

Used 43+ times

FREE Resource

3 Slides • 12 Questions

Angle Addition

Angle Types

Adjacent Angles are two angles that share a side and a vertex.
Vertical Angles are opposite angles that are created by intersecting lines. Vertical angles are CONGRUENT (equal).

Multiple Choice

Vertical angles are always

acute

total 180 degrees

congruent (equal measures)

adjacent angles

Multiple Choice

What angle pair is pictured?

Alternate Interior Angles

Supplementary Angles

Vertical Angles

Corresponding Angles

Multiple Choice

Name the vertical angle to

∠h.

∠f

∠i

∠g

∠j

Multiple Choice

Which are pairs of vertical angles?

∠COB & ∠COA

∠AOD & ∠AOC

∠COB & ∠AOD

∠BOD & ∠AOD

Multiple Choice

Which angles are vertical angles?

$\angle8\ \&\ \angle7$

$\angle8\ \&\ \angle6$

$\angle8\ \&\ \angle5$

Multiple Choice

What type of angles are these?

Adjacent Angles

Linear Pair

Complementary Angles

Supplementary Angles

Vertical Angles

Angle Addition Postulate

A mathematical rule that states that if we have two adjacent angles, we can add their measures to find the measure of the big angle they create.
Small angle + small angle = big angle... so if you know two small angles and need to know the big angle, ADD.
If you know the big angle and one of the small angles and need to know the other small angle, SUBTRACT.

Multiple Choice

Calculate m∠ABC.

45°

60°

105°

15°

Multiple Choice

Find the value of ∠A.

25 degrees

30 degrees

35 degrees

90 degrees

Multiple Choice

Calculate m∠DEF.

180°

60°

120°

80°

Multiple Choice

$\angle ECD=122\degree$ and $\angle BCE=36\degree$ . Find the measure of $\angle BCD$ .

$\angle BCD=158\degree$

$\angle BCD=86\degree$

$\angle BCD=58\degree$

$\angle BCD=144\degree$

Multiple Choice

Find the value of ∠A.

39 degrees

49 degrees

51 degrees

59 degrees

Multiple Choice

What is the measure of the missing angle?

166

156

Angle Addition

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