Question

An electrician has to repair and electric fault on the pole of height 5m. She needs to reach a point 1.3m below the top of the pole to undertake the repair work.What should be the lengthof the ladder that she should use which,when inclined at an angle of 60 to the horizontal,would enable to reach the required position? Also,how far from the foot of the pole should she place the foot of the ladder? (you may take√3=1.73).

Answer 1

length of the ladder is 4.267m and distance from the pole is 2.133m

Answer 2

Hi!

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{ BDC is a right-angled triangle in this case}

She is required to reach the point B on the pole AD

BD = AD - AB

BD = ( 5 - 1.3)

BD = 3.7 m

Finding Hypotenuse ( Length of the ladder )

Sin 60° = $\frac{BD}{BC}$

$\frac{\sqrt{3} }{2} =  \frac{3.7}{BC}$

BC = $\frac{3.7 * 2 }{\sqrt{3} }$

=>  4.28 m

Finding the foot of the ladder  placed by her at a distance of 2.14 m from the pole

$\frac{DC}{BD}$ = Cot60° = $\frac{1}{\sqrt{3} }$

DC = $\frac{3.7}{\sqrt{3} }$ = 2.14 m ( approx . )

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Thanks !!