Definition of an exterior angle
At each vertex of a triangle, an exterior angle of the triangle may be formed by extending ONE SIDE of the triangle. See picture below.
Calculating the Angles
We can use equations to represent the measures of the angles described above. One equation might tell us the sum of the angles of the triangle. For example,
x + y + z = 180
Answer:

Can I have the brainliest please?
Answer:
To find the area, you have to multiply its height by its width.
Step-by-step explanation:
Answer:
x = 15
Step-by-step explanation:
The two angles form a straight line so they add to 180 degrees
3+6x + 5x+12 = 180
Combine like terms
11x+15 = 180
Subtract 15 from each side
11x+15-15 =180-15
11x = 165
Divide by 11
11x/11 =165/11
x =15
Answer:
1,436.8
Step-by-step explanation: