# Find the measure of Angle x?

• May 29th 2009, 10:29 AM
hellotarina
Find the measure of Angle x?
What is the measurement for that angle x?

Thank you (Wink)
• May 29th 2009, 10:52 AM
HallsofIvy
By the "vertical angles" theorem, when two lines cross, angles opposite one another have the same measure. So one of the angles inside the triangle is also x. Another angle in the triangle has measure 60 for the same reason and the third is "supplementary" to an angle with measure 140 so it has measure 180- 140= 40 degrees. Of course, the angle in the triangle must sum to 180 degrees. Can you find x now?
• May 29th 2009, 10:53 AM
skeeter
Quote:

Originally Posted by hellotarina
What is the measurement for that angle x?

you need to use the following facts ...

1. a linear pair is supplementary
2. vertical angles have equal measure
3. the sum of the angles of any triangle is 180 degrees
• May 29th 2009, 11:13 AM
hellotarina
Is this right? x=40 or look at pic
• May 29th 2009, 12:31 PM
craig
Quote:

Originally Posted by hellotarina
Is this right? x=40 or look at pic

No I'm afraid not.

From you diagram you can see one angle is is 40, one is 63. Using the internal angle fact about triangles provided above, this means that the last internal angle, and therefore x, is...