Luas bangun datar di atas adalah....

d = 42 cm
r = 42/2
r = 21 cm

L 1/2 lingkaran
= 1/2 x phi r²
= 1/2 x 22/7 x 21²
= 11/7 x 21²
= 11/7 x 441
= 11 x 63
= 693 cm²

L persegi panjang
= p x l
= 78 x 42
= 3.276 cm²

L gabungan
= 693 + 3.276
= 3.969 cm²