goteachmaths.co.uk Parallel Lines

01 December 2018 Parallel Lines

ANGLES: Measure & Label Angles A & B. A + B = ? A B Measure & Label Angle C. Calculate or Measure Angle C C D What is the rule we can use? Measure & Label Angle A & C. What do you notice? Calculate or Measure Angle B Can you calculate Angle D? A D B C Measure & Label Angle A. Can you calculate ALL the other angles? B A What is the rule we can use? D C

Exam Vocabulary Measure = use a protractor Calculate = use angle rules!

1 2 3 110° Angles in a straight line = 180° A + B = 180 ° A B A Angles in a full turn = 360° A + B + C + D = 180 ° 2 D B C Vertically Opposite Angles are equal A = C B = D A 3 D B C

120° 110° E A 70° 60° F 60° 45° B 90° 135° G 140° C 40° 85° 50° 85° H D 50° 55° 55° J 40° I

Parallel Lines are the same distance apart… forever.

Parallel Lines are the same distance apart… forever.

Parallel Lines are the same distance apart… forever.

Parallel Lines Investigation.

Measure Angle A to the nearest 5° Calculate Angles B, C & D Measure Angles E, F, G, H D A C B E F What do you notice? G H Measure Angle A to the nearest 5° Calculate Angles B, C & D Measure Angles E, F, G, H A B D C What do you notice? F E H G

Extension! Write rules for: 1) The connection between B & F 2) The connection between C & F 2) The connection between C & G Super Extension: Draw a similar diagram in your book and check your three rules.

(transversal line)

ALTERNATE Angles are Equal

ALTERNATE Angles are Equal CORRESPONDING Angles are Equal

ALTERNATE Angles are Equal CORRESPONDING Angles are Equal CO-INTERIOR Angles = 180°

A A A x = 130° x = 130° x = 130° A A A x = 130° x = 130° x = 130°

B B B x = 95° x = 95° x = 95° B B B x = 95° x = 95° x = 95°

C C C x = 45° x = 45° x = 45° C C C x = 45° x = 45° x = 45°

D D D x = 70° x = 70° x = 70° D D D x = 70° x = 70° x = 70°

E E E x = 140° x = 140° x = 140° E x = 140° x = 140° x = 140°

F F F x = 81° x = 81° x = 81° F F F x = 81° x = 81° x = 81°

G G G x = 99° x = 99° x = 99° G G G x = 99° x = 99° x = 99°

H H H x = 35° x = 35° x = 35° H H H x = 35° x = 35° x = 35°

I I I x = 110° x = 110° x = 110° I I I x = 110° x = 110° x = 110°

J J J x = 80° x = 80° x = 80° J J J x = 80° x = 80° x = 80°

K K K x = 70° x = 70° x = 70° K K K x = 70° x = 70° x = 70°

EXTENSION Parallel Parkour 70° e f l i j k d h c g m 50° a b a = 70°

EXTENSION Draw parallel lines and a transversal line. Measure one angle. Name (x) one angle. Challenge your partner to find the missing angle. Make it as hard as possible with multiple parallel lines and transversal lines.