tolong dijawab ya Please!! Pakai cara nya

1. (1/2×10×10×2)+(3×10)=100+30=130 m
2. (7×7)+(37×7)=49+259=308cm
3. (8×8)+(4×8)+(1/2×3×4×2)=64+32+12=108 cm
4. (1/2×8×21)+(1/2×8×9)+(6×6)=84+36+36=156 cm