220 Basic Engineering Mathematics
(a)
(c)
(b)
(d)
(e)
(f)
Figure 25.1
B
A
C
D
Figure 25.2
Q
P
R
S
Q
P
R
S
Figure 25.3
W
Z
Y
X
Figure 25.4
A
␣ ␣
␤ ␤
D
C
B
Figure 25.5
E
H
G
F
Figure 25.6
Trapezium
In the trapezium EFGH shown in Figure 25.6,
(a) only one pair of sides is parallel.
Problem 1. State the types of quadrilateral shown
in Figure 25.7 and determine the angles marked a
to l
(a)
(b)
(c)
(d)
(e)
B
A
x
x
a
C
D
E
H
G
F
d
c
b
408
308
K
J
x
x
L
M
e
f
O
Q
P
j
i
h
g
N
658
528
R
U
T
S
k
358
758
1158
l
Figure 25.7
(a) ABCD is a square
The diagonals of a square bisect each of the right
angles, hence
a =
90 ◦
2
= 45
◦
(b) EFGH is a rectangle