There is one exterior angle for a missing internal angle. The exterior angle has a measure of 130 degrees.
An exterior angle and interior angle will always add up to 180. To find this missing internal angle, set the internal and external angle to equal 180:
[tex]130 + x = 180[/tex]
x represents the value of the missing internal angle.
Subtract 130 from both sides to get x by itself:
[tex]x = 50[/tex]
The value of x will be 50.
The missing internal angles both have the same angle. All internal angles must add up to 180 in a triangle. We can represent this by setting up an equation:
[tex]50 + y + y = 180[/tex]
[tex]y + y = 2y[/tex]
[tex]50 + 2y = 180[/tex]
Subtract 50 from both sides:
[tex]2y = 130[/tex]
Divide both sides by 2 to get y by itself:
[tex]\boxed{y = 65}[/tex]
The value of y will be 65.
