Answer:1385.44mm sq
Step-by-step explanation: surface area of a circle = pi x radius squared
3.142 x 21 squared
Answer:
Step-by-step explanation:
diameter = 42 mm
radius (r) = 42/2 = 21mm
SA of semicircle = 3πr²
[tex]=3*\frac{22}{7}*21*21\\\\=3*22*3*21\\\\=4158mm^{2}[/tex]
