Angle of Elevation

• Sep 17th 2009, 09:49 AM
Naples
Angle of Elevation
A driveway is built on a slant where it rises 3m over a distance of 20m, what is the angle of elevation with the ground?

I'm not sure if the 20m should be the adjacent leg or the hypotenuse.
• Sep 17th 2009, 10:03 AM
e^(i*pi)
I would say it's the adjacent side, it would be unusual to describe the hypoteneuse when it would be much easier to describe the adjacent
• Sep 18th 2009, 03:40 AM
aidan
Quote:

Originally Posted by Naples
A driveway is built on a slant where it rises 3m over a distance of 20m, what is the angle of elevation with the ground?

I'm not sure if the 20m should be the adjacent leg or the hypotenuse.

This is a Building Construction problem.
ALL dimensions are given as horizontal & vertical - or vertical & horizontal - NEVER diagonal.
Stair Step: tread & riser
Roof Pitch: Horizontal Distance & Vertical Distance
Sewer Flow: 1% (translates to 1 foot vertical drop per 100 feet horizontal travel).

These are the easiest methods to layout & build.
Most carpenters use the slope/hypotenuse ONLY as a check -- never to setup to build.

In your question you are give the vertical rise over a horizontal distance.
The 20m is the adjacent side.
• Sep 19th 2009, 04:48 AM
pacman
"A driveway is built on a slant where it rises 3m over a distance of 20m, what is the angle of elevation with the ground?I'm not sure if the 20m should be the adjacent leg or the hypotenuse."

in a civil engineer arena, you do measure base and height

grade = y/x = height/base

height = 3 m

base = 20

not necessary: slant height = sqrt (20^2 + 3^2) = sqrt 409 = 20.22375 m

angle of elevation = arctan (grade) = arctan (y/x) = arctan(height/base) = ?

you may read this: Grades, Highway | Macmillan Mathematics Summary

(Rock)