429 cm²
A(blue) =
= 2×6cm×10cm + 2×6cm×8cm + 8cm×10cm + (8cm×10cm - 5cm×4cm)
= 120cm² + 96cm² + 80cm² + 60cm²
= 356 cm²
A(green) =
= 4cm×5cm + 2×5cm×5cm/2 + 4cm×7cm
= 20cm² + 25cm² + 28cm²
= 73 cm²
A(total) =
= A(blue) + A(green)
= 356 cm² + 73 cm²
= 429 cm²
