$1.$ Create the class diagram for a class named Circle with fields named radius, area, and diameter. Include get methods for each field, but include a set method only for the radius.

Also write the pseudocode for the class and include a constructor that sets the radius to $1.$

When the radius is set, do not allow it to be zero or a negative number. When the radius is set, calculate the diameter $($twice the radius$)$ and the area $($the radius squared times pi$,$ which is approximately $3\mathrm{.}14).$

Code to go into the setRadius$()$ method:

if rad $<=0$ then

radius $=1$

else

radius $=$ rad

endif

diameter $=2*$ radius

area $=($radius $*$ radius$)*3\mathrm{.}14$