Area of a triangle (1)

1 Completethesentencestodescribe

thetriangle.

Thetrianglehas fullsquares.

Thetrianglehas halfsquares.

Theareaofthetriangle

is cm2

2 Countsquarestoworkouttheareaofeachtriangle.

a) c)

area= cm2

b)

area= cm2 area= cm2

3 Countsquarestoestimatetheareaofeachtriangle.

a) c)

area= cm2 area= cm2

b)

area= cm2

Whyareyouranswersestimates?

4 a)Workouttheareasoftheshapesbycountingsquares.

area= cm2 area= cm2

©WhiteRoseMaths2019

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area= cm2

d)

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1cm

b) Whatdoyounoticeaboutyouranswerstoparta)?

Explorethisusingotherrectangles.

c) Writeyourfindings.

5 Drawatrianglethathasanareaofapproximately15cm2

Compareanswerswithapartner.

©WhiteRoseMaths2019

6

DoyouagreewithEva’sestimate?

Talkaboutitwithapartner.

7 Drawtriangleswiththeseareas.

1cm22cm23cm24cm25cm26cm2

Talktoapartneraboutthebeststrategiesfordrawing

thetriangles.

I estimate the size of the triangle to be about 16 cm2

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