A ladder leans against a vertical wall. Upper End of the ladder is 8 m above the ground. When the lower end of the ladder is moved 2 m farther away from the wall, the other end of the ladder rests against the foot of the wall. The length of the ladder is:
Answer & explanation
Correct answer: option 4
By using the pythagoras theorem,
P² + B² = H²
8² + B² = A²
64 + B² = A²
& A = 2 + B
64 + B² = (2 + B )²
64 + B² = 4 + B² + 4B
4B = 60
B = 15
So, A = 15 +2 = 17 m
So length of ladder = 17 m