Answer:

Step-by-step explanation:
Area of a Circle: 
The r is the length of the radius of the circle
The radius of the shown circle is 9 m


Answer:
300L per hour
Step-by-step explanation:
The rate of change of volume of blood pumped by the teenager's heart expresses the volume of blood pumped with respect to hour.
Rate of change of volume of blood = 
= 
= 300L/hour
The rate of change of volume of blood by the teenager's heart is 300 litres per hour. This implies that his/ her heart pumps 300 litres of blood every hour.
If one square is divided into 9 smaller equal squares, then they have to be arranged in 3 lines of 3, that is 3 smaller equal squares per side of the original big square. That said, the area of the big square is equal to the multiplication of 3 small squares sides times 3 small squares sides, call x the length of the small squares.
So,
area = 9 = 3x*3x
9x^2 = 9
x^2 = 1
x = 1
therefore the smaller squares have sides of 1 unit