Finding Angle B in Triangle: Step-by-Step Guide

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In summary, the conversation is about finding angle B in a right triangle with a given angle C of 55 degrees. The sum of angles in a triangle is 180 degrees. The x-axis makes a 90 degree angle with the y-axis. The sum of angles B and C is also 90 degrees. In the attached image, another angle D is labeled in blue and it is equal to angle C because the lines labeled "x" and the slope incline are parallel. This is because they are cut by a transveral.
  • #1
hvidales
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Homework Statement


Find angle B

Homework Equations


Triangle makes 180 degrees

The Attempt at a Solution


I brought the red vector(Red Vector was given) down more to make a right triangle and got 55 degrees for C. I do not know where to go from there though to get angle B. Angle B is also 35 degrees but I don't know how they got that.
[url=http://postimage.org/][PLAIN]http://s17.postimage.org/6onxtnlbz/Untitled.png[/url][/PLAIN]
 
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  • #2
The line labeled "x" is parallel to the slope incline. The lines labeled "x" and "y" are presumably perpendicular. You should be able to take it from there.
 
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  • #3
hvidales said:

Homework Statement


Find angle B

Homework Equations


Triangle makes 180 degrees

The Attempt at a Solution


I brought the red vector(Red Vector was given) down more to make a right triangle and got 55 degrees for C. I do not know where to go from there though to get angle B. Angle B is also 35 degrees but I don't know how they got that.

[url=http://postimage.org/][PLAIN]http://s17.postimage.org/6onxtnlbz/Untitled.png[/url][/PLAIN]
What angle does the x-axis make with the y-axis ?
 
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  • #4
SammyS said:
What angle does the x-axis make with the y-axis ?

90 degrees
 
  • #5
hvidales said:
90 degrees

Then, what is the sum of (angle B) + (angle C) ?
 
  • #6
SammyS said:
Then, what is the sum of (angle B) + (angle C) ?

would it be 90 too? I also had another question, the angle where B is at, is that whole piece a another right triangle?
 
  • #7
See attachment. I labeled another angle, D, in blue. Given that the line labeled "x" and the slope incline are parallel, what can you say about angles C and D?
 

Attachments

  • Incline.png
    Incline.png
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  • #8
Are they equal to each other?
eumyang said:
See attachment. I labeled another angle, D, in blue. Given that the line labeled "x" and the slope incline are parallel, what can you say about angles C and D?
 
  • #9
hvidales said:
Are they equal to each other?
Yes.
 
  • #10
eumyang said:
Yes.

oh so these are two parallel lines cut by a transveral right?
 
  • #11
hvidales said:
oh so these are two parallel lines cut by a transveral right?
Again, yes.
 

FAQ: Finding Angle B in Triangle: Step-by-Step Guide

What is the formula for finding Angle B in a triangle?

The formula for finding Angle B in a triangle is B = 180 - (A + C), where A and C are the other two known angles in the triangle.

Can you explain the steps for finding Angle B in a triangle?

Step 1: Identify the two known angles in the triangle, A and C.
Step 2: Add A and C together.
Step 3: Subtract the sum from 180.
Step 4: The result is Angle B.

What if I only know the length of the sides of the triangle, can I still find Angle B?

Yes, you can use the Law of Cosines to find Angle B. The formula is B = arccos[(a^2 + c^2 - b^2)/(2ac)], where a, b, and c are the lengths of the sides of the triangle.

Is there a faster way to find Angle B in a right triangle?

Yes, if you know the lengths of the sides of the right triangle, you can use the trigonometric function tangent (tan). The formula is tan(B) = opposite/adjacent. Solve for B by taking the inverse tangent (tan^-1) of the result.

Can you provide an example of finding Angle B in a triangle?

Example: In a triangle, Angle A is 40 degrees and Angle C is 60 degrees. To find Angle B, we use the formula B = 180 - (A + C). Thus, B = 180 - (40 + 60) = 80 degrees. Therefore, Angle B is 80 degrees.

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