Luas Lingkaran

Luas Lingkaran =  $\pi$  x  $\frac{D}{2}\ x\ \frac{D}{2}$  

 Luas Lingkaran = $\pi\ x\ \frac{D}{2}\ x\ \frac{D}{2}$  =  $\frac{22}{7}\ x\ \frac{21}{2}\ x\ \frac{21}{2}\ =\ \frac{11}{1}\ x\ \frac{3}{1}\ x\ \frac{21}{2}$  = 346,5

Luas Lingkaran =  $\pi\ x\ r\ x\ r$  =  $\pi\ x\ r^2$  

Luas Lingkaran =  $\pi\ x\ r\ x\ r\ =\ \frac{22}{7}\ x\ 7\ x\ 7\ =\ 22\ x\ 7\$  =  $154cm^2$  

Luas lingkaran =  $\pi\ x\ \frac{D}{2}\ x\ \frac{D}{2}\ =\ 3,14\ x\ 20\ x\ 20\$  

=  $\frac{314}{100}\ x\ 20\ x\ 20\ =\ 314\ x\ 4\$  

= 1.256 $cm^2$  

Luas = 3,14 x 10 x 10 =  $\frac{314}{100}\ x\ 10\ x\ 10=\ 314cm^2$