The figure, not drawn to scale, is made up of 2 triangles, KRS and PRS. KL is
12 of PQ. MN is
78 of KL and the difference between PQ and MN is 81 cm. Given that SR = 20 cm, find the area of the entire figure.
KL |
PQ |
MN |
1x8 |
2x8 |
|
8x1 |
|
7x1 |
8 u |
16 u |
7 u |
9 u = 81 cm
1 u = 81 ÷ 9 = 9 cm
Length of KL
= 8 u
= 8 x 9
= 72 cm
Length of PQ
= 16 u
= 16 x 9
= 144 cm
Length of MN
= 7 u
= 7 x 9
= 63 cm
Area of Triangle KRS
=
12 x 20 x 72
= 720 cm
2 Area of Triangle PSR
=
12 x 20 x 144
= 1440 cm
2 Area of Triangle MSR
=
12 x 20 x 63
= 630 cm
2 Area of the figure
= 720 + 1440 - 630
= 1530 cm
2 Answer(s): 1530 cm
2