The figure, not drawn to scale, is made up of 2 triangles, GNP and LNP. GH is
12 of LM. JK is
56 of GH and the difference between LM and JK is 21 cm. Given that PN = 18 cm, find the area of the entire figure.
GH |
LM |
JK |
1x6 |
2x6 |
|
6x1 |
|
5x1 |
6 u |
12 u |
5 u |
7 u = 21 cm
1 u = 21 ÷ 7 = 3 cm
Length of GH
= 6 u
= 6 x 3
= 18 cm
Length of LM
= 12 u
= 12 x 3
= 36 cm
Length of JK
= 5 u
= 5 x 3
= 15 cm
Area of Triangle GNP
=
12 x 18 x 18
= 162 cm
2 Area of Triangle LPN
=
12 x 18 x 36
= 324 cm
2 Area of Triangle JPN
=
12 x 18 x 15
= 135 cm
2 Area of the figure
= 162 + 324 - 135
= 351 cm
2 Answer(s): 351 cm
2