Ditanyakan= Pajang Busur AB?

[tex]kab = \frac{ {45}^{0} }{ {360}^{0} } \times 2\pi \: r \\ = \frac{1}{8} \times 2 \times \frac{22}{7} \times 7 = 5.5 \: cm[/tex]

a) K = 2 π r
        = 2 x 22/7 x 7
        = 44 cm²
b) L = π r²
       = 22/7 x 7²
       = 154 cm²
c) Luas juring AOB = (α°/360°) x Luas lingkaran
                               = (45°/360°) x 154
                               =  19,25 cm²
d) panjang busur AB = (α°/360°) x Keliling lingkaran
                                  = (45°/360°) x 44
                                  = 5,5 cm