# question on triangometry, where i can put angle

• Oct 14th 2010, 01:46 AM
r-soy
question on triangometry, where i can put angle
I face problem when i try to put the angle into the drwing

like .... :

Attachment 19329

http://www.mathhelpforum.com/math-he...isc/pencil.png
• Oct 14th 2010, 02:36 AM
r-soy
• Oct 14th 2010, 02:44 AM
HallsofIvy
Quote:

Originally Posted by r-soy
I face problem when i try to put the angle into the drwing

like .... :

Attachment 19329

http://www.mathhelpforum.com/math-he...isc/pencil.png

You have triangle ABC with B the right angle. You are told there is a bridge across a chasm 30 m wide and that is at side AB. You are told the bridge is "20 degrees from the horizontal". Since The chasm, side AB, is "horizontal", it is angle A that is 20 degrees. And the height of the bridge, in going from one side to the other is the length of side BC.
• Oct 14th 2010, 02:48 AM
HallsofIvy
Quote:

Originally Posted by r-soy

First, you have 3m in the wrong place. The way you have drawn it, B is the right angle. 3m is the length of the hypotenuse and that is always the side opposite the right angle (the longest side in a right triangle). Once that is done, you are free to put the 30 degrees at either A or C because which is the "near side" and which is the "opposite side" will depend upon where you put the angle.

If you choose to put the 30 degrees at angle A, then BC is the "opposite side" and AB is the "near side". If you choose to put the 30 degrees at angle C, then BC is the "near side" and AB is the "opposite side".

Those two different choices for where to put the 30 degrees angle will give different answers for the length of AB and BC but the same answers for "near side" and "opposite side".
• Oct 15th 2010, 08:56 AM
r-soy
thanks

In quaesion one we wil put the angle on A becuse (20 degrees from the horizontal )

correct ??