Answer:
stack AD with bar on top space text is parallel to end text BC with bar on top.
2. Angle Addition Postulate as they are adding both angles
3. 60 + 40 = m <ABC because it's a substitution
4. 100 = m <ABC as it is simplified already
5. Definition of obtuse angle
The proportion equal to a/b = c/d is A.) A/C = B/D
We will know if a proportion is equivalent when its cross products are equal.
a/b = c/d where ad = bc
since ad = bc, a/c = b/d
Answer:
x = 7cm
Step-by-step explanation:

There is no solution. Here is the explanation with both of the methods :)