Question

http://prntscr.com/2t30ky

Answer 1

\(\bf \textit{mid segment of a trapezoid}=\cfrac{base1+base2}{2}\\ \quad \\
\implies EF=\cfrac{AB+DC}{2}\implies 8.8=\cfrac{12.6+x}{2}\)

Answer 2

^ah yes. now only I got to learn that about a trapezoid. thanks for the question @musa19965

Answer 3

i don't get it

Answer 4

^It's actually a theorem

Answer 5

http://www.mathsisfun.com/geometry/trapezoid.html