Question

Luas setengah lingkaran 157 cm2. Berapa diameter lingkaran itu ?

Answer 1

L = 1/2 x 3,14 x r²
157 = 1,57 x r²
100 = r²
10 = r

d = 2r = 20

Answer 2

Luas stengah lingkaran = π x r² x 1/2
157                               = 3,14 x r² x 1/2
157/3,14 x 2                      = r²
50         x 2                        = r²
√100                                  = r
10                                      = r

diameter = 2 x jari jari
diameter = 2 x 10
               = 20 cm
jadi, diameternya adalah 20 cm