Question

For problems 14 and 15, a drain pipe is to be laid between 2 points. One point is 15

feet higher in elevation than the other. The pipe is to slope at an angle of 12° with
the horizontal.
Find the length of the drain pipe. Round to 2 decimal
places.

Answer 1

Length of the drain pipe is 72.15 feet.

Explanation:

From the figure attached,

A drain pipe is to be laid between two pints P and Q.

Point P is 15 ft higher than the other point Q.

Angle of elevation of point P from point Q is 12°.

Let the length of pipe is l feet.

By applying Sine rule in the given right triangle PRQ,

Sin(∠Q) =
`\frac{\text{Opposite side}}{\text{Adjacent side}}`

Sin(12) =
`\frac{\text{PR}}{\text{PQ}}`

0.20791 =
`(15)/(l)`

`l=(15)/(0.20791)`

`l=72.146`

l = 72.15 ft

Therefore, length of the drain pipe is 72.15 feet.