Grade 8 GEOMETRY OF STRAIGHT LINES

• Complementary Angles

• Supplementary Angle

• Both Complementary and Supplementary Angle

• Neither

Answer explanation

115+65=180

Supplementary Angles

• Add up to 90

• Supplementary Angles

• Complementary Angles

• Neither

Answer explanation

5x - 60 + 150 - 5x = 90

Complementary Angles

Answer explanation

x + 145 = 180

x = 180 - 145

x = 35

Solve for x

(a)  

Answer explanation

2x+40+x+20=180

3x=120

x=40

• x=67
• y=127

• x=65
• y=113

Answer explanation

It's Ok read Property 2

Calculate all the unknown angles with reasons

• a = 93

  Co-interior Angles

• c = 93

  Alternate Angles

• b = 93

  Vertically Opposite angles

• P1 = 118

  Angles on a straight line

• c = 118

  Corresponding Angles

Answer explanation

a = 93 Co-interior angle(EF//MN)

b = 93 Vertically Opp Angles

P1 = 118 (angles on a Straight line)

c = 118 (Corresponding Angles EF//MN)

Answer explanation

Angle BEF =180-2x (co - interior angles AB//CD)

y = 180 - 2x (Vertically Opposite angles)