Basic Geometry : Triangles
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Example Questions
Example Question #3 : How To Find An Angle In A Right Triangle
Angle 
The interior angles of a triangle always add up to 180 degrees. We are given angle 
Angle 
Example Question #4 : How To Find An Angle In A Right Triangle
Which of the following cannot be true of a right triangle?
The measures of the angles of a right triangle can total 
One leg can be longer than the hypotenuse.
A right triangle can have an obtuse angle.
None of the other statements can be true of a right triangle.
A right triangle can be equilateral.
None of the other statements can be true of a right triangle.
All of these statements are false.
A right triangle can be equilateral.
False: An equilateral triangle must have three angles that measure 
One leg can be longer than the hypotenuse.
False: Each leg is shorter than the hypotenuse.
A right triangle can have an obtuse angle.
False: Both angles of a right triangle that are not right must be acute.
The measures of the angles of a right triangle can total 
False: The measures of any triangle total 
Example Question #2 : How To Find An Angle In A Right Triangle
In triangle 
The formula to find all the angles of a triangle is:
To solve for the measure of angle 
Example Question #1 : How To Find An Angle In A Right Triangle
Find the degree measure of the missing angle.
All the angles in a triangle add up to 180º.
To find the value of the remaining angle, subtract the known angles from 180º:
Therefore, the third angle measures 43º.
Example Question #2 : How To Find An Angle In A Right Triangle
The right triangle 
The internal angles of a triangle always add up to 180 degrees, and it was given that the triangle was right, meaning that one of the angles measures 90 degrees.
This leaves 90 degrees to split evenly between the two remaining angles as was shown in the question.
Therefore, each of the two equal angles has a measure of 45 degrees.
Example Question #1 : How To Find An Angle In A Right Triangle
What is the missing angle in this right triangle?
The angles of a triangle all add up to 
This means that 
Using the fact that 90 is half of 180, we can figure out that the missing angle, x, plus 34 adds to the remaining 90, and we can just subtract
Example Question #2 : How To Find An Angle In A Right Triangle
Solve for 
The angles of a triangle add together to 180 degrees. We already know that one of the angles is 90 degrees, so we can subtract 90 from 180: the other 2 angles have to add to 90 degrees.
We can now subtract to get x:
Example Question #11 : How To Find An Angle In A Right Triangle
Determine the missing angle in this right triangle:
The angles of a triangle always add to 180 degrees.
That means that in this case,
There are a few ways we can move on from here, but one is to simplify this equation:
Example Question #12 : How To Find An Angle In A Right Triangle
Find the measurement of 
Recall that the angles inside of a triangle must add up to 
Thus, for the triangle in question,
Example Question #13 : How To Find An Angle In A Right Triangle
Find the measurement of 
Recall that the angles inside of a triangle must add up to 
Thus, for the triangle in question,
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