dibantu ya kakak semua

2)a L=1/2×phi×r×r
L=1/2×22/7×7×7
L=77cm2
b L=s×s
=40×40
=160cm2
L=1/2×phi×r×r
=1/2×22/7×14×14
=11×2×14
=308cm2
Larsir=308cm2-160cm2
=148cm2