1. Nov 16, 2006

### grego89

This is a force problem the 2 green angles in the question are equal I have to explain why they are equal

how am I suppoused to figure this out I really need help

when you click on the link and then click on the picture you can make it bigger

2. Nov 16, 2006

### Staff: Mentor

This is a geometry/trig issue. Consider angles that add to 90 degrees. You'll find that A + C = 90 and B + C = 90, so you can conclude that A = B.

If you study your diagram, you'll see how this logic can be applied. Hint: Label the angles and see which ones form right angles or add up to 90 degrees.

3. Nov 16, 2006

### grego89

I really dont get what you mean I have a right angle in the big triangle and a right angle in the small triangle I label one angle a and one angle b what about the remaining two sides of the 2 triangles

4. Nov 16, 2006

### physics girl phd

Things that might help: If you exaggerate the angle, you might see things better -- Try to make the incline really steep or not very steep. Then be careful about drawing it well. Look carefully at the normal.

5. Nov 16, 2006

### grego89

So basically the green angle from the big triangle and the other angle which we label as C equals 90

and the green angle from the small triangle and the other angle which we also labeled c equals 90?

6. Nov 16, 2006

### Staff: Mentor

Sounds like you've got it. (As long as you realize that it's the same angle "c" in both cases.)

7. Nov 16, 2006

### civil_dude

If that line is perp. to that line, and the other line is perp. the the other line, then the angles between them are the same.....

In so many words, so to speak.