Question

Exercitiul 28 va rog

Answer 1

a)OA=3 cm    m(∡AOB)=30°
A=3×3×sin 30°/2=(9×1/2)/2=9/4=2,25
Asector cerc=π×r²×30°/360°=3,14×3²/12=2,355
Ahasurata=2,355-2,25=0,105 cm²

b)OA=5 cm    m(∡AOB)=45°
A=5×5×sin 45°/2=(25×√2/2)/2=25√2/4=6,25√2=8,8375
Asector cerc=π×r²×45°/360°=3,14×5²/8=9,8125
Ahasurata=9,8125-8,8375=0,975 cm²

c)OA=10 cm    m(∡AOB)=60°
A=10×10×sin 60°/2=(100×√3/2)/2=100√3/4=25√3=43,30
Asector cerc=π×r²×60°/360°=3,14×10²/6=52,(3)
Ahasurata=52,(3)-43,3=9,0(3) cm²