Question

Two walls and a ceiling of a room meet

at right angles at a point P. A fly is in
the air 1 m from one wall, 8 m from
the other wall and 9 m from the point
P. How many meters is the fly from the
ceiling?

Answer 1

The position of the fly is shown as cross in the diagram below

The distance of the fly from the ceiling is given as
`y`

We need to work out the distance
`x` to be able to work out the value of
`y`

by the Pythagoras theorem


`x^(2) = 8^(2) + 1^(2)`

`x^(2) =65`

`x= √(65)`

by Pythagoras theorem


`y= \sqrt{9^(2)- ( √(65) )^(2) }`

`y = √(16) =4`

The distance of the fly from the point P is 4m