Support Reactions of a Trapezoidal Slab with Three Points of Support

Situation
A reinforced concrete slab in the shape of an isosceles trapezoid weighs 3600 N/m2. It is supported on the three points as shown in the figure.
 

eq-parallel-forces-trapezoid-slab.gif
  1. Find the reaction at A.
    A.   16,848 N
    B.   6,716 N
    C.   13,372 N
    D.   2,010 N
  2. Find the reaction at B.
    A.   16,848 N
    B.   6,716 N
    C.   13,372 N
    D.   2,010 N
  3. Find the reaction at C.
    A.   16,848 N
    B.   6,716 N
    C.   13,372 N
    D.   2,010 N