Answer:

Step-by-step explanation:
<u>Step 1: Add 4 to both sides
</u>



Answer: 
1: right triangle, 2: right triangle, 3: not a right triangle, 4:not a right triangle.
We have been given that r is parallel to s. Now, if we look at angle 5 and angle 1, we can see that they are corresponding angles on parallel lines. Corresponding angles are ALWAYS equal, so therefore, your answer is 128 degrees; option A! :)
Hope this helped!
< BAC = 50
< BCA = 90
interior angles of a triangle add up to 180
so < ABC = 180 - (90 + 50) = 180 - 140 = 40
and < ABC = < CDE.......so < CDE = 40 <===