Respuesta :

Answer:

628.3 cm

Step-by-step explanation:

The window has a semicircle shape = half of a circle

Perimeter of the window = ½(πr²)

Radius (r) = 20 cm

Plug in the value

Perimeter of the window = ½(π*20²)

= ½(π*400)

Perimeter of the window = 628.31853 ≈ 628.3 cm (nearest tenth)