Basic Engineering Mathematics, Fifth Edition

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 angleθ in diagrams
   (a) to (i) of Figure 20.10.

1208

(a)



558 508

(c)



(^608808)
(f)


(e)
708
1508

378
(d)

(g)
50.7 8 
(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 lineXY?Giveexamplesof
   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 angleα.

137  29 

16  49 



Figure 20.12

10. In Figure 20.13, find anglesa,bandc.

c a

b

298

698

Figure 20.13

11. Find angleβin Figure 20.14.

133 

98 



Figure 20.14

12. Convert 76◦to radians, correct to 3 decimal
    places.


13. Convert 34◦ 40 ′to radians, correct to 3 deci-
    mal places.


14. Convert 0.714 rad to degrees and minutes.