50 points!

let abcd be a parallelogram. by definition of a side ab is parallel to side cd and side bc is parallel to side da. construct diagonals bd and ac using a straightedge. label the point of intersection between the diagonals point q. according to a property of a opposite sides are congruent so side ab is congruent to side cd. ∡bac is congruent to ∡acd and ∡abd is congruent to ∡bdc, both by thetheorem. therefore, rabq and rcdq are congruent by aq is congruent to cq and bq is congruent to dq by consequently, diagonals bd and ac bisect one another by definition of a bisector.