(a) Describe briefly the Gunters’ chain.
(b) A farmer surveyed his triangular farmland with a base length of 2 km and a perpendicular length of 1200m. Calculate the area of the farm.
(c) State four necessary precautions that should be taken in order to eliminate errors when chaining a farmland.
(d) List four factors required in choosing a site for a new school garden.
Explanation
(a) The Gunter's chain consists of a brass handle at each end. The chain is entirely metallic. It consists of units, each of which is a straight piece and three oral rings. The commonest length available is 30.5m.
(b) Given Base length of farm 2km =200m, Perpendicular length = 1200m, Area of farm = 1/2(base x height) = 1/2(2000m x 1200m) = (24000000m²2) = 1200000m² or 1.2km² Alternatively: Base length of farm, = 2km Perpendicular length = 1200m, = 1.2km Area of farm = 1/2 (base x height) 1/2 (2km x 1.2km) 1/2 (2.4 km2) 1.2 km²
(c) Necessary precautions to be taken in order to eliminate errors when chaining farm land are: (i) pulling of taut chains, tapes or ropes. (ii) avoidance of errors of transposing figures on papers. (iii) equipment such as theodolite should be placed on a perfect horizontal plane. (iv). all chains, tapes, ropes, etc. must be properly alligned before taking measurement (v) avoidance of error of parallax when reading measurements. (v) make sure the chain is not faulty before use.
(d) Factors to be considered when choosing a garden site for a school include: (i) topography (ii) drainage (iii) availability of good top soil (iv) adequa water supply (v) closeness to the school (vi) good access road from the school to the garden.