Jawaban:

titik berat = lingkaran besar - lingkaran kosong

lingkaran besar

A1 = πr² = π36

x1 = jari jari = r = 6

y1 = r = 6

lingkaran kosong

A2 = π9

x2 = 3 + r = 3 + 3 = 6

y2 = r = 3

titik berat

x = (A1 x1 - A2 x2)/(A1-A2)

x = (36π x 6 - 9π x 6 )/(36π-9π)

x = 162/27 = 6

y = (A1 y1 - A2 y2)/(A1-A2)

y = (36π x 6 - 9π x 3 )/(36π-9π)

y = 189/27 = 7

no2

titik berat = segiempat+segitiga miring

segiempat

A1 = pxl = 6x12 = 72

x1 = ½p = 3

y1 = ½L = 6

segitiga miring

A2 = ½ alas x tinggi = ½ x 12 x6 = 36

x2 = 6 + 1/3 tinggi = 6 + 1/3 x 6 = 8

y2 = ½ alas = ½ x 12  = 6

titik berat

x = (A1 x1 + A2 x2)/(A1+A2)

x = (72x3 + 36x8)/(72+36) = 504/108 = 4,67

y = (A1 y1 + A2 y2)/(A1+A2)

y = (72x6 + 36x6)/(72+36) = 648/108 = 6

Penjelasan: