Hi there!
There are many ways to find the measure of an exterior angle of a triangle. I'll explain the easiest method to you. As you can see in the image, a line is drawn extending a side of the triangle. In order to find the measure of the exterior angle, we can subtract the measure of the
adjacent interior angle from 180 (a straight angle). Doing this subtraction will give us the measure of the exterior angle.
Hope this helps!! :)
0.88888889
just devide 8 by 9
The coordinates of vertex B' is
.
<h3>
How to calculate the coordinate of point by reflection</h3>
A point if reflected across the line
by means of the following formula:
(1)
Where:
- Original point
- x-Coordinate of point P
- Resulting point
If we know that
and
, then the coordinates of the vertex is:
![P'(x,y) = (-2, 4) + 2\cdot [(-2,-2)-(-2,4)]](https://tex.z-dn.net/?f=P%27%28x%2Cy%29%20%3D%20%28-2%2C%204%29%20%2B%202%5Ccdot%20%5B%28-2%2C-2%29-%28-2%2C4%29%5D)



The coordinates of vertex B' is
. 
To learn more on reflections, we kindly invite to check this verified question: brainly.com/question/1878272
(4,-3) i took the test i'm 100% sure
i hope i helped ;)