RESOLVED: How do I calculate an angle

[AMG.]

I used to be quite good at geometry and such but that was 35 years ago .
I need your help to refresh my mind.

I have triangle that is 87 units horizontal and 3 units vertical. I need to work out the # of degrees of the sharpest angle (a).

Formula: tan a = 3/87 = 0.0345 = ?? degrees.

I have access to the scientific Bill Gates Windows XP calulator and it has a TAN button on it but I'm not sure how to work this out.

I found an example on the web and tried to replicate it using the sam calculator but couldnt get their answer.
Their example was: tan <a = 5/12 = 0.417 <a= 23 degrees

What do I punch in and in which sequence?
Appreciate your help.

AMG.

 

[Famine]

I used to be quite good at geometry and such but that was 35 years ago .
I need your help to refresh my mind.

I have triangle that is 87 units horizontal and 3 units vertical. I need to work out the # of degrees of the sharpest angle (a).

Formula: tan a = 3/87 = 0.0345 = ?? degrees.

I have access to the scientific Bill Gates Windows XP calulator and it has a TAN button on it but I'm not sure how to work this out.

I found an example on the web and tried to replicate it using the sam calculator but couldnt get their answer.
Their example was: tan <a = 5/12 = 0.417 <a= 23 degrees

What do I punch in and in which sequence?
Appreciate your help.

AMG.

You're missing just one step. According to SOHCAHTOA (yikes), the Tan of the angle is the length of the Opposite divided by length of the Adjacent.

So 3/87 gives you the Tan of the angle (0.03448). You need the angle, so you need to calculate the inverse Tan...

3/87 = 0.03448
Tan^-1 x 0.03448 = 1.97 degrees.


And just so you know, I was scratching my head for 20 minutes until I twigged what was missing.

 

[Boundary Layer]

Close,

Your equation is set up properly. To find 'a' in degrees take the inverse tan of 3/87 (if using a scientific calculator make sure it is set to 'degree' mode, not radians).

a = tan ^-1 (3/87)
a = 1.975°

edit: treed, but at least it only took me 2 minutes to type it up, and not twenty

 

[Danoff]

I need to work out the # of degrees of the sharpest angle (a).

Does sharpest mean smallest or largest? We're dealing with a right triangle here right?

Don't forget to convert you answer to degrees.

 

[Boundary Layer]

Most acute. Given the description (units horizontal and vertical) it is a right triangle

 

[Danoff]

Most acute. Given the description (units horizontal and vertical) it is a right triangle

I had noticed. It was really just a prompt to make sure that AMG thinks about it more than anything.

Edit: AMG, make sure you don't try to raise the tan result to -1, there is an inverse tangent button.

 

[Sage]

AMG: For future reference, remember that whenever you&#8217;re solving for a variable, you usually want the variable completely by itself. That&#8217;s where you went wrong &#8211; solving for tan(a) instead of a.

 

[daan]

Wanders into thread

looks around

wanders back out wondering what just happened there

 

[AMG.]

Wanders into thread

looks around

wanders back out wondering what just happened there

, you had me in stitches!.


Ah, yes it is a right triangle!
Thx guys but euh... how do I punch this in to Gates' scientific (set to degrees) calculator

3/87, enter, tan => 0.000601etc doesnt seem right.

Sorry I can really be blond sometimes.

 

[Famine]

Just check the "Inv" box before you click "Tan".

 

[Boundary Layer]

, you had me in stitches!.


Ah, yes it is a right triangle!
Thx guys but euh... how do I punch this in to Gates' scientific (set to degrees) calculator

3/87, enter, tan => 0.000601etc doesnt seem right.

Sorry I can really be blond sometimes.

On the left side where you have your trig/exponential/whatever functions you'll notice two checkboxes. 'Inv' for Inverted, and 'Hyp' for hyperbolic (I assume). Do your 3/87, enter... but before hitting 'tan', put a check in the 'Inv' box.

edit: DAMMIT FAMINE!

 

[AMG.]

👍 x tan x 1.000.000!!!

+ rep to the both of you.
That really helped.

 

[daan]

edit: DAMMIT FAMINE!

Want me to delete his post for you?

 

[Boundary Layer]

👍 x tan x 1.000.000!!!

+ rep to the both of you.
That really helped.

hey, careful with those negative 4th quadrant thumbs-ups. You can confuse a guy like that.

However, I'll welcome a 👍 x tan x 1'000'169

Want me to delete his post for you?

If you would be so kind ...