From triangle midsegment theorem we know, that a midsegment connecting two sides of a triangle is parallel to the third side and is half as long, so:
1.
Midsegment length = 6x+4
Third side length = 4x+56
and

so midsegment length:

Answer C.
2.
The tree is a midsegment so it is half as high as a building:

Answer A.