The area of a triangle is calculated by multiplying the base and the height, then dividing that value by 2.
(1/2)bh
The triangle must be isosceles, due to the perpendicular bisector. Therefore, the expression 20 - 15 can be used to yield an answer of B. 5.
Hope this helps!
a. The average value of
on the given interval is

b. Solve for
:

The value of 4 is 4000, this is because it is in the thousands column (units,tens,hundreds,thousands etc)
Mixed number=4 8/10=4 4/5
improper fraction=48/10=24/5