The area, A, of a trapezium is given by the formula:
A = (h/2)(a + b) where h is the height of the trapezium and a and b are the lengths of the parallel sides.
From the problem statement, we know that A = 105 cm2 and (a + b) = (5 cm + 9 cm) = 14 cm. h is the unknown height we are trying to find. Now plug these values back into the formula for the area of a trapezium:
105 = (h/2)*(14) = h*7
Now you can solve for h.