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: |
10 m 15 m 30 m 17 m |
17 m |
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
|