what is the area of the compact disc
to find the area use the formula πr2 (that 2 should be superscript meaning rxr or r squared)
where r is the radius of the circle
so in your case;
r = 6
=3.14 x (6 squared)
=3.14 x 36
A = ÏrÂ²
A = Ï * 6Â²
A = 36Ï
A â 113.09733552923255658465516179806
The area is approximately 113.097 centimetres.
Incidentally, I somehow managed to have @ least 1 CD & a ruler in front of me. Turns out, the radius of a compact disc is almost six centimeters.
Do a 2nd calculation of the void in the middle of the disc if it is required
to get a true area..
area of a CD = area of the outer circle(R=6) - are of the inner circle[void](r= 1.5 / 2)
=> Pi * R^2 - Pi * r^2
=> Pi (R^2 - r^2)
=>Pi (R + r) (R-r)
=>22/7 (13.5 / 2) ( 10.5 / 2)
=>3.14 * 6.75 * 5.25
=> 111.27375 sq.cm
note: pi = 22/7 or 3.14
a^2 - b^2 = (a+b)(a-b)