How Do I Find An Unknown Angle Measure?

14 Answers

Joe Gilbert Profile
Joe Gilbert answered
If you need to know the value of an unknown angle in a triangle or a quadrilateral, this is a problem that is common in middle school mathematics. To get the correct answer, simply add the sum of the degrees of the other angles and subtract that amount from 180. The result of that will be the correct answer. This and other simple problems are the key to have a student succeed in the subject of geometry and if you have a child in the middle school age you should drill them on problems such as this to prepare them for more complicated equations that they will see in their high school years.

Geometry is the study of the shape and size of relative positions of figures and properties of space. It is one of the very oldest of the mathematical sciences. It has many practical uses in other fields such as astronomy. Since the mapping of the stars and planets and relationships between movements of celestial bodies is done by relating them to known objects on the celestial sphere, geometry has long been used in this field.

When Descartes introduced coordinates and algebra was developed, this marked a new stage of development for the science of geometry. Now complex geometric figures such as plane curves could be represented in an analytical fashion with functions as well as with equations. This was the event that directly led to the development of calculus in the 17th century.

Geometry also has use in many other scientific fields and in new theories such as string theory. It continues to this day as one of the most important foundations in the field of mathematics and it should be mastered before a student tries to tackle more difficult subjects such as calculus and differential equations.
Anonymous Profile
Anonymous answered
Take Note.
Triangle- Equal 180 degrees
Quadrilateral- Equals 360 degrees.

Okay. So you already know..
1 side equals- 64
2 side equals- 58
3rd side equals 98
And you want to know what the 4th side equals.
So first you will add up all the sides they give you.
  64
+58
  98
______
  220

So as I said before, a quadrilateral is 360 degrees.
The figure only equals up to 220.
So you are going to subtract.
220 from 360.
  360
- 220
_____
  140 degrees!

And that is your answer!
I hope I helped.
Anonymous Profile
Anonymous answered
Okay. Depending on how many angles the shape has. A triangle's angle measurements will always add up to 180 degrees. Then you add 180 degrees for each extra vertex. So a quadrilateral will have 360 degrees. A pentagon will have 540 degrees and so on. Since this question only asks for 1 unknown angle. All you need to do is count all the angles up. When you get to 3 angles. It will always be 180 degrees. The measurements may not match if the shape has more than 3 angles. So you start adding 180X to 180 degrees. X is the variable for angles after 3 angles. When you find the total. You then: For example a shape with 6 angles would have 720 degrees. So add up all the other angles. Let's say it adds up to 653 degrees. You then take 720 and subtract 653 to get the missing angle which is 67 degrees.

If this wasn't what you're looking for I'm sorry.  :)
Anonymous Profile
Anonymous answered
Take Note.
Triangle- Equal 180 degrees
Quadrilateral- Equals 360 degrees.

Okay. So you already know..
1 side equals- 64
2 side equals- 58
3rd side equals 98
And you want to know what the 4th side equals.
So first you will add up all the sides they give you.
  64
+58
  98
______
  220

So as I said before, a quadrilateral is 360 degrees.
The figure only equals up to 220.
So you are going to subtract.
220 from 360.
  360
- 220
_____
  140 degrees!

And that is your answer!
I hope I helped.
Anonymous Profile
Anonymous answered
Find the unknown angle of 42
Aisha Profile
Aisha answered
The total angles should equal to 360 degrees if this is a four sided figure. The 3 angles measure 64+58+98 = 220 therefore the remainder becomes 360 -220 = 140 degrees
Anonymous Profile
Anonymous answered
How to find a unkown angle is that all angles equal 180 degrees so there should be one angle you no so you subtract that from 180.
Anonymous Profile
Anonymous answered
I do I find a measure if it is a 4 sided figure and they give you only 1 measurement.
Anonymous Profile
Anonymous answered
Of a triangle? Or a rectangle?
If it's a triangle or an angle, then it's not possible.
They must add up to; 180, 90 or 360.

There you go.

Hope it helps, next time be more specific in what TYPE you're looking for.
Anonymous Profile
Anonymous answered
How do I find an unknown angle of a triangle if they are 135 and 15 and the other one is blank?   PLEASE HELP ME OUT!!!! THANK YOU!

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