The point-slope form of a line is:
y-y1=m(x-x1), where m=slope and (x1,y1) is any point on the line
First we need to find the slope, which is (y2-y1)/(x2-x1)
m=(4--1)/(8-2)
m=5/6 and we can use either point, I'll use (8,4)
y-4=(5/6)(x-8)
That is your equation in point-slope form.
Now the standard equation of a line is ax+by=c
y-4=(5/6)(x-8) we can perform the indicated multiplication on the right side
y-4=(5x-40)/6 multiply both sides by 6
6y-24=5x-40 add 24 to both sides
6y=5x-16 subtract 5x from both sides
-5x+6y=-16 and by convention, the standard equation of a line should be expressed with a positive coefficient for x, so multiply both sides by -1
5x-6y=16
Combine like terms for 30c +3d
Answer:
pi x diameter
Step-by-step explanation:
To find the circumference of any given circle, multiply the radius by 2 to get the diameter, and then the diameter by pi (3.14)