2.(408+6)/3= 138

3. At the last second of 14, the overlapping area of rectangle and triangle is-10 * 10/2 = 50.

(2) the first -(6+ 18)/2 = 12- the last second, the overlapping area of rectangle and triangle is 18cm?

4. Not necessarily

5.0.098...98 Round to the nearest one percent (0. 100).

6. Calculate the volume of this semi-cylinder as 3.14 * 8 * 8 *12 =1004.8.