Motivation
You may need the material of this chapter for:
- the study of structures – from molecular and crystalline to ‘big’ engineering
- computer aided design
- problems in statics
- coordinate geometry (Chapter 7)
- vector algebra and its applications (Chapter 11)
- applications in differentiation and integration (Chapters 8, 9, 10)
5.1 Review
5.1.1 Division of a line in a given ratio ➤147 160➤➤
A lineABof length 30 cm is divided internally by a pointPin the ratio 3 : 2. Find the
lengths ofAPandPB. Repeat for the case whenP dividesABexternally in the same
ratio.
5.1.2 Intersecting and parallel lines and angular measurement
➤148 160➤➤
A.Give the angles in (a) degrees (b) radians corresponding to the following fractions of
a full revolution
(i)
1
2
(ii)
1
3
(iii)
1
4
(iv)
1
12
(v)
3
4
(vi)
5
8
B. Ifl 1 ,l 2 are straight lines, name and evaluate the missing angles.
a 40 °
b c
l 1
l 2
Figure 5.1