Question 154550
Remember:
{{{A=pi(d^2)/4}}} -------------------------------> working eqn
For 5mm{{{sigma}}}:
{{{A[1]=pi(5^2)/4}}}
{{{A[1]=19.625mm^2}}}
for 7mm{{{sigma}}}:
{{{A[2]=pi(7^2)/4}}}
{{{A[2]=38.465mm^2}}}
The difference: {{{A[2]-A[1]=38.465-19.625=18.84mm^2}}}
Thank you,
Jojo