(a) A woman looking out from the window of a building at a height of...

MATHEMATICS
WAEC 2009

(a) A woman looking out from the window of a building at a height of 30m, observed that the angle of depression of the top of a flag pole was 44°. If the foot of the pole is 25m from the foot of the building and on the same horizontal ground, find, correct to the nearest whole number, the (i) angle of depression of the foot of the pole from the woman ; (ii) height of the flag pole.

(b)geometric In the diagram, O is the centre of the circle, < OQR = 32° and < TPQ = 15°. Calculate, (i) < QPR ; (ii) < TQ°.

Explanation

(a)angle of elevation and depression

(i) From \(\Delta\) TFO,

\(\tan x = \tan \theta\) (alternate angles)

\(\tan x = \frac{25}{30} = 0.8333\)

\(x = \tan^{-1} (0.8333)\)

= \(39.80° \approxeq 40°\)

Angle of depression of the pole from the woman

= 90° - 40°

= 50°.

(ii) From \(\Delta\) TPQ,

\(\tan 46 = \frac{25}{TQ}\)

\(TQ = \frac{25}{\tan 46}\)

\(TQ = \frac{25}{1.0355}\)

= \(24.1429 m\)

Height of the pole : \(TF - TQ\)

= \(30 m - 24.1429 m\)

= \(5.8571 m\)

\(\approxeq 6m\)



Post an Explanation Or Report an Error
If you see any wrong question or answer, please leave a comment below and we'll take a look. If you doubt why the selected answer is correct or need additional more details? Please drop a comment or Contact us directly. Your email address will not be published. Required fields are marked *
Add Math
Don't want to keep filling in name and email whenever you make a contribution? Register or login to make contributing easier.