no 15 diatas pakai jalan

a). CB² = 12² +16²
CB² = 144 + 256
CB² = 400
CB = √400
CB = 20cm
diameter = 20cm

jari" = 20:2 = 10cm

b).L½lingkaran
=½×π×r²
=½×3,14 ×10×10
=157cm²

Lsegitiga
=½ × a × t
=½ × 12 × 16
=96cm²

Larsiran = 157-96
=61cm²

diket :
alas segitiga = 12cm
tinggi segitiga = 16cm

ditanya =
a. r = ?
b. L diarsir = ?

jawab :
a.
r = 1/2 d
d = sisi miring segitiga
d^2 = 12^2 + 16^2
d^2 = 144 + 256
√d = √400
d = 20
r = 1/2 × 20 = 10 cm

b.
L diarsir = L 1/2 lingkaran - L segitiga
L diarsir = 1/2 × π × r × r - 1/2 × a × t
L diarsir = 1/2 × 3,14 × 10 × 10 - 1/2 × 12 × 16
L diarsir = 157 - 96
L diarsir = 61 cm2