The lengths of the parallel sides of a trapezium are 9 cm and 12 cm. lf the area of the trapezium is 105 cm

^{2}, find the perpendicular distance between the parallel sides.-
**A.**

5cm -
**B.**

7cm -
**C.**

10cm -
**D.**

15cm

##### Correct Answer: Option C

##### Explanation

(frac{1}{2}(a+b)times h = 105cm^2\

frac{1}{2}(9+12)times h = 105\

h = frac{105 times 2}{21} = 10cm)