Answer:
The required equation is
.
Step-by-step explanation:
The equation of line cd is

Slope intercept form of a line is

Where, m is slope and b is y-intercept.
Slope of line cd is 3.
The product of slopes of two perpendicular lines is -1.



Therefore slope of perpendicular line is
.
Point slope form of a line is

Slope of perpendicular line is
and line passing through the point (3,1).



Therefore the required equation is
.
B
The formula for circumference is

d, or Pi times diameter
Answer:

Step-by-step explanation:
Using the rule of exponents
⇔
, then
=
= 