Answer:
∠?=40°
Step-by-step explanation:
Remember that in a line AND a triangle there are <u>180 degree</u>s.
You correctly found the third angle in the left triangle to be 69°, Now plug it into the equation for a line, including 71°:
<u>69°+71°+x=180°</u>
1) Combine the degrees:
140°+x=180°
2) Subtract 140° from both sides:
x=40°
We have now found the bottom left angle for the triangle on the right to be 40°
To find the angle labeled "?" You must plug in all of the known angles of the triangle to be equal to 180°:
40°+100°+x=180°
1) Combine the degrees:
140°+x=180°
2) Subtract 140 from both sides:
∠?=40°
The answers tell you the y-intercept is zero, so all you need to do is choose the appropriate slope. Since y/x = -4, ...
.. selection A is appropriate.
