angles in a triangle work out the sizes of the unknown angles. · 2020-04-28 · 3 work out the...
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![Page 1: Angles in a triangle Work out the sizes of the unknown angles. · 2020-04-28 · 3 Work out the unknown angles. a) Ac) q = s = b) d) r = t = Discuss your reasons with a partner. 4](https://reader033.vdocument.in/reader033/viewer/2022042222/5ec8c3883f6ea505c57d9a10/html5/thumbnails/1.jpg)
Angles in a triangle
1 Hereisatriangle.
a) Thethreeverticesaretornoffthetriangleandarrangedona
straightline.
Whatisthesumofthethreeangles?
Howdoyouknow?
b) Nowmeasurethesizesofanglesa,bandcinthetriangle.
a= b= c=
c) Whatisthetotalofanglesa,bandc?
d) Completethesentence.
Anglesinatriangle©WhiteRoseMaths2020
a
b
c
ab
c
2 Workoutthesizesoftheunknownangles.
Givereasonsforyouranswers.
a)
x= because
b)
y= because
c)
z= because
d)
w= because
x
92°
47°
y
z
w
58°
31° 28°
25°
35°
![Page 2: Angles in a triangle Work out the sizes of the unknown angles. · 2020-04-28 · 3 Work out the unknown angles. a) Ac) q = s = b) d) r = t = Discuss your reasons with a partner. 4](https://reader033.vdocument.in/reader033/viewer/2022042222/5ec8c3883f6ea505c57d9a10/html5/thumbnails/2.jpg)
3 Workouttheunknownangles.
a) c)
q= s=
b) d)
r= t=
Discussyourreasonswithapartner.
4 a) Twoanglesinatriangleare42°and57°.
Whatisthesizeofthethirdangle?
b) Twooftheanglesinatriangleare12°.
Whatisthesizeofthethirdangle?
c) Oneoftheanglesinatriangleis38°.Anotherangleistwicethe
sizeofthefirstangle.
Whatisthesizeofthethirdangle?
©WhiteRoseMaths2020
5 Sortthetrianglesintothetable.
0acuteangles 1acuteangle 2acuteangles 3acuteangles
Areanyofthecolumnsempty?Why?
6
DoyouagreewithRon?
Explainyouranswer.
p = 143° because angles in a triangle sum to 180°
and 180 – 37 = 143
37°
p
q
t
s
r
88.4°
72°
47.3°
19.5° 21.5°
42.1°
23.2°
101.6°
A B
C D E
35°
95°
65°
58°
58°
34°
96°61°