Respuesta :

Answer:

42 cm^2

Step-by-step explanation:

Base = 21 cm

Height = 4 cm

Area = [tex]\frac{base\times height}{2}[/tex]

Substitute values into the given equation

[tex]A = \frac{21\times 4}{2} \\\\A = \frac{84}{2} \\\\A = 42cm^2[/tex]