Question

Please solve this question as soon as possible
pls answer in full steps

Answer 1

construction of DB such that it intersects EF at M.

now, since EF II AB and E is midpoint,
M is midpoint of DB     (i)
EM= AB/2           (from midpoint theorem) (ii)
 similarly, since EF II AB and M is midpoint,
F is midpoint of CB
FM = CD/2 (from midpoint theorem) (iii)
 Adding (ii) and (iii),
EM+ FM = 1/2(AB +CD)
EF = 1/2(A+B)