Question

Find the areas of the following
in centimetres.
(a)
5
(L
6
5
18​

Answer 1

Answer

(i)Area of triangle

1

=

2

(11)(22)

=121cm

2

Area of triangle

2

=

2

(16)(22)

=176cm

2

Area of quadrilateral=121+176=297cm

2

(ii)9

2

+12

2

=81+144=225

225

=15

Area of triangle=

2

(15)(16)

=120cm

2

Perimeters=

2

9+12+15

=18

Area of triangle=

18(18−15)(18−9)(18−12)

=

2916

=54cm

2

Area of quadrilateral=120+54=174cm

2

(iii)Area of triangle

1

=

2

(27)(12)

=162cm

2

Area of triangle

2

=

2

(27)(10)

=135cm

2

Area of quadrilateral=162+135=297cm

2☺☺

Answer 2

Answer

(i)Area of triangle

1

=

2

(11)(22)

=121cm

2

Area of triangle

2

=

2

(16)(22)

=176cm

2

Area of quadrilateral=121+176=297cm

2

(ii)9

2

+12

2

=81+144=225

225

=15

Area of triangle=

2

(15)(16)

=120cm

2

Perimeters=

2

9+12+15

=18

Area of triangle=

18(18−15)(18−9)(18−12)

=

2916

=54cm

2

Area of quadrilateral=120+54=174cm

2

(iii)Area of triangle

1

=

2

(27)(12)

=162cm

2

Area of triangle

2

=

2

(27)(10)

=135cm

2

Area of quadrilateral=162+135=297cm

2