8.34 Chapter 8
Find the area of the polygon in each of the following figures. [Nos. 21-24]
21. 22.
y
x
J(3,1)
O
H(3,-4)
G(-2,-4)
E(-4,4)
F(-2,0)
y
x
C(12,-6)
B(-4,-6)
A(-4,6)
O
23. 24.
A(- 4,6 )
F(- 12,2)
D(2,-4)
E(-10,-4)
B(2,2 )
C(-1,2 ) y
x
O
E(- 5,4 )
G(5,2)
F(-2,- 2) y
x
O
25. (a) Draw a pentagon ABCDE with vertices A(-7 , 4), B(-2 , -3),
C(0 , -3), D(5 , 4) and E(-1 , 0) in a rectangular coordinate
plane.
(b) Find the area of pentagon ABCDE.
26. (a) Draw a pentagon HJKLM with vertices H(1 , 4), J(-1 , 1),
K(0 , -1), L(2 , -1) and M(3 , 1) in a rectangular coordinate
plane.
(b) Find the area of pentagon HJKLM.
27. Given that the area of quadrilateral OPQR in the figure is
25.5 sq. units, find the coordinates of R.
28. Given that the area of polygon ABCDEFGH in the figure is
14 sq. units, find the value of y.
➥ Example 10
➥ Example 11
y
x
O
Q(-9,3) P(-4,3)
R
y
x
B (- 1,y) A (1,y)
C(-1,- 1)
O
H (1,- 1)G(3,- 1)
D (- 3,-1)
E (- 1,- 3) F(1,- 3)
3
2
2
4
4
2
3
3
33.5 sq. units 72 sq. units
27 sq. units
97 sq. units
25 sq. units
12 sq. units
(0 , -4)
2