tolong donk kk......mendadak ni.

NO. 2
Kel. lingkaran= 2 x π x r
= 2 x 3,14 x 50cm
= 2 x 157,0
= 314,0/314 cm
NO. 3
L. segitiga= 1/2 x alas x tinggi
= 1/2 x 42cm x 58cm
= 1/2 x 2436 cm
= 1218cm²
NO. 4
L. layang²= 1/2 x diagonal 1 x diagonal 2
= 1/2 x 30cm x 36cm
= 1/2 x 1080cm
= 540 cm²