Step 1: Analyse the given information and Draw a figure.
GIVEN: The pole height AB = 9 m

Height of the electric pole to do repair = AB - BC = 9 - 1.8 = 7.2
Angle between the ladder and the ground = 60\degree
Length of the ladder = ?
The distance between the foot the ladder and foot of the pole AD = ?
Step 2: Find the length of the ladder by using the trigonometric ratios
NOTE: From right triangle ADC, we know the opposite side and we have to calculate the hypotenuse.
So take the \sin \theta = \frac{opposite}{hypotenuse}
EXAMPLE: \sin 60\degree = \frac{AC}{DC}
\frac{\sqrt{3}}{2} = \frac{7.2}{DC} ( \because \sin 60\degree = \frac{\sqrt{3}}{2} )
DC = \frac{2*7.2}{\sqrt{3}}
Simplify the above equation by Rationalizing
DC = \frac{2*7.2}{\sqrt{3}} \frac{\sqrt{3}}{\sqrt{3}}
DC = \frac{14.4*\sqrt{3}}{3}
DC = 4.8 * 1.732
DC = 8.3136 m
Height of the ladder = 8.3136 m
Step 3: Calculate the distance between the foot the ladder and foot of the pole by using the trigonometric ratios.
NOTE: From right triangle ADC, we know the opposite side and we have to calculate the adjacent side.
So take the \tan \theta = \frac{opposite}{hypotenuse}
EXAMPLE: \tan 60\degree = \frac{AC}{AD}
\sqrt{3} = \frac{7.2}{AD}
AD = \frac{7.2}{\sqrt{3}}
Simplify the above equation by Rationalizing
AD = \frac{7.2}{\sqrt{3}} \frac{\sqrt{3}}{\sqrt{3}}
AD = \frac{7.2*\sqrt{3}}{3}
AD = \frac{7.2*1.732}{3}
AD = 2.4 * 1.732
AD = 4.1568 m
The distance between the foot the ladder and foot of the pole = 4.1568 m