a) latura patratului = diamterul cercului =30 cm=> raza= diametrul/2=30/2=15 cm
Lcercului=2Ï€ x r=2Ï€ x 15= 30Ï€
b) Apatrat= l^2=30^2=900
A cerc= π x r^2=π x 15^2=225π
A suprafata hasurata=900-225Ï€=225(4-Ï€)
c) BD-diagonala=>BD= l√2=30√2
Fie {P}=BD ∩ C(O,r)
d(B; C(O;r)=PB
PB=[tex] \frac{30√2-15}{2} [/tex]