jika diameter nya 42 brp luas setengah lingkaran tsbut tlg dibantu kk brainly...

r = d : 2
= 42 : 2 = 21

L = phi x r²
= 22/7 x 21 x 21
= 1386 : 2
= 693

diameter=42 cm
jari-jari = 21 cm
luas setengah lingkaran??
π x r x r = 22/7 x 21 x 21
= 22 x 3 x 21
= 1.386 cm : 2
= 693 cm²