The formula that you will use will be the formula for the area of a circle, which is as follows:
A= Pi r^2
(Pi times the radius squared)
Answer:
B) The scale on the y-axis could be changed to 25–40.
the coordinates of the points of intersection of the graph of y=13−x with the axes
Given equation is y=13-x
x axis is x=0
y axis is y=0
Plug in the value of x =0 and find out y
y = 13 - x
y = 13 - 0 = 13
Plug in the value of y=0 and find out x
0 = 13 - x
x= 13
So coordinate axis
x= (13,0)
y= (0,13)
Base of the triangle is x=13
Height of the triangle is y= 13
Area of the triangle = 
=
= 84.5
Area of the triangle = 84.5
Plant with treatment A in general grow more than plants with treatment B.
Picture below.