Ex 6.5, 9
A ladder 10 m long reaches a window 8 m above the ground. Find the distance of the foot of the ladder from base of the wall.
Given :-
Height of window = AC = 8m
Length of ladder = AB = 10 m
To Find : Distance of foot of ladder from wall i.e. BC
Solution:
Since the wall will be perpendicular to ground
ACB = 90
ACB is a right angle triangle
So, using Pythagoras theorem
(Hypotenuse)2 = (Height)2 + (Base)2
(AB)2 = (AC)2 + (BC)2
(10)2 = (8)2 + (BC)2
100 = 64 + (BC)2
100 64 = (BC)2
36 = (BC)2
(BC)2 = 36
BC = 36
BC = (6 6)
BC = ((6)2)
BC = 6 m
Hence, distance of the foot of the ladder from base of the wall (BC) = 6 m.

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Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.