170 Basic Engineering Mathematics
4. State the general name given to an angle of
90
◦ .
5. Determine the angles complementary to the
following.
(a) 69 ◦ (b) 27 ◦ 37 (c) 41 ◦ 3 43
6. Determine the angles supplementary to
(a) 78
◦ (b) 15
◦ (c) 169
◦ 41
11
7. Find the values of angle θ in diagrams
(a) to (i) of Figure 20.10.
1208
(a)
␪
558
508
(c)
␪
608
808
(f)
␪
␪
(e)
708
1508
␪
378
(d)
␪
(g)
50.78
␪
(h)
1118
688
458
578
␪
(i)
368
␪
708
(b)
␪
Figure 20.10
8. With reference to Figure 20.11, what is the
name given to the line XY? Give examples of
each of the following.
x
y
1
4
5
8
3
2
7
6
Figure 20.11
(a) vertically opposite angles
(b) supplementary angles
(c) corresponding angles
(d) alternate angles
9. In Figure 20.12, find angle α.
137Њ29Ј
16Њ49Ј
␣
Figure 20.12
10. In Figure 20.13, find angles a, b and c.
a
c
b
298
698
Figure 20.13
11. Find angle β in Figure 20.14.
133Њ
98Њ
␤
Figure 20.14
12. Convert 76 ◦ to radians, correct to 3 decimal
places.
13. Convert 34 ◦ 40 to radians, correct to 3 decimal places.
14. Convert 0.714 rad to degrees and minutes.