Triangle Calculation

[sealo0]

Hi

Just wondered if someone could help?

I have a long series calc to do for the adjacent side of a triangle.

I know Angle 'a' 40deg therefore Angle 'c' = 50degs and angle 'b' =90degs. the only known size is 180mm or multiples of 180. ie 360, 540 etc

How do I put this into a cell?

Thanks in advance

Mike Seal

 

[Eric W]

With a 90 degree angle, you have a right triangle, which means the Pythagorean theorem applies. You didn't say what side the known size applies to, either the hypotenuse or a leg. To get the length of the other 2 sides, try the Law of Sines. To get the area, get the sides first and use 1/2bh, where b and h are the 2 legs. All of these formulas convert quite easily from the equation form to an Excel formula.

 

[sealo0]

Hi Eric

Thanks for the replay. The 180mm is ‘a’ up from the 90degs.

Hope that helps

Mike

 

[BadgerRoad]

That still doesn't explain where the angles are. Is angle a (40 degrees) adjacent to side a or opposite side a?

 

[sealo0]

Hi all. Thanks for the replies.

I knew I should have done this in the first place!

‘X’ is the required size.

Thanks again for your help.
Mike

 

[BadgerRoad]

The formula is the length of the side times the tangent of angle a. Since Excel calculates trig functions in radians instead of degrees you have to convert the angle to radians using the RADIANS function. So the formula is as follows:
=180*tan(radians(50))

 

[sealo0]

Hi

Many thanks for that.

Mike seal