Vertically opposite angles

1 Thediagramshowsfouranglesformedbytwostraightlines.

a) Measurethesizesoftheangles.

a= b= c= d=

b) Whatisthetotalofanglesaandb?

Explainwhy.

Doanyotherpairsofangleshavethissametotal?

c) Anglesaandcareverticallyoppositeangles.

Whatdoyounoticeaboutthesizesofanglesaandc?

d) Anglesbanddarealsoverticallyoppositeangles.

Whatdoyounoticeaboutthesizesofanglesbandd?

e) Completethesentence.

Verticallyoppositeangles

2 Tickthepairsofanglesthatareverticallyopposite.

Compareanswerswithapartner.

3 Workoutthesizesoftheunknownangles.

Givereasonsforyouranswers.

a)

y= because

b)

z= because

©WhiteRoseMaths2020

a b

y

z

29°

132°

48°

cd

4 Annieisworkingoutthesizeofanglef.

DoyouagreewithAnnie?

Explainyouranswer.

5 Workouttheunknownangles.

a) c)

a= c=

b) d)

b= d=

©WhiteRoseMaths2020

e) f)

e= f=

Talkaboutyourreasonswithapartner.

6 Anglebisthreetimesthesizeofanglea.

Workoutthesizesofanglesaandb.

a= b=

7 Anglefisonequarterofthesizeofangleg.

Anglefis28°.

Areanglesxandyverticallyopposite?

Explainyouranswer.

Angle f is equal to 79° because vertically opposite

angles are equal.

f

79°

e

f

81°

113°

a

b

d

c

133°

73°

81°65°

52°

a

b80°

gf

139°

yx