Count every four-sided figure in a trapezium that has both diagonals and a line across its middle parallel to its top and bottom.

With the top edge as a side: the whole trapezium, the part above the middle line and two between the top edge, a diagonal and the line, 4. With the base as a side: the part below the line and three more cut by the diagonals, 4. Two kite-like shapes each have a top corner, the crossing point and two points on the line, 2. Total $4+4+2=10$.