Q5 of 68 Page 9

In the figure, ABC is a right triangle in which AB = 8 m, ∠BCA = 30°, then find

(i) the angle of elevation of A at C.


(ii) the angle of depression of C at A.


(iii) BC and AC


(i) From the diagram, it is clear that the angle of elevation of A with respect to C is 30˚ where BC becomes the horizontal.


(ii) DC is a vertical line drawn from A so that we get a reference line from which we can measure the depression angle.


As AD and BC are both vertical lines therefore they are parallel.


Now ∠ACB = ∠CAD as they are alternate angles along two parallel lines


therefore, ∠ CAD = 60˚


Now, from the diagram drawn before we can easily say that


The angle of depression of C at A is 60˚


(iii)




BC = 8√3m


Now,




or,



AC = 16m.


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