Angles

[toddha510]

I just need to know what formula I would use to find the answer. I know the answer but I have to show my work and my book doesnt have the formula to solve it. So I am going to give you the question and the answer and then maybe someone can tell me what formula to use.

Two angles of a triangle are equal. Their sum is the measure of the third angle. What are the measurements?


Now I know that it is a 45, 45, 90 triangle. 45+45+90=180.

What formula do I use in order to show my work?

 

[mmm4444bot]

Use this "formula":

The sum of the three interior angles of any triangle = 180 degrees

In your exercise, you're told that two of the interior angles are equal (an Iscosceles triangle). Pick a symbol to represent these two equal angles.

x = angle1

x = angle2

You're told that the third angle is the sum of the other two.

x + x = angle3

Using the "formula" above, we can write an equation that shows the sum of the interior angles 1, 2, and 3 to be 180 degrees.

x + x + (x + x) = 180

Solve for x, to find angle1 and angle2.

Double the result, to find angle3.

MY EDITS: The usual grammar errors.

 

[Aladdin]

----------------------

45 , 45 , 90 .

Right isosceles triangle ~ 45 + 45 = 90

 

[toddha510]

Thanks for the help!