Semicircles With Algebra

What is the formula for area of a semicircle?

• A =  $\frac{1}{2}$  π

• A =  $\frac{1}{2}$  πr

• A =  $\frac{1}{2}$  πr²

Find the area of this Semicircle with a diameter of 18 cm. (Take π = 3.14)   

• 254.34 cm

• 127.17 cm

• 56.52 cm

• 28.26 cm

Find the area of this quarter circle with a radius of 6 cm. (Take π = 3.14)

• 56.52 cm

• 113.04 cm

• 28.26 cm

• 37.68 cm

Xuan Rong placed the 'WELCOME' mat shown on her front door step. What is the area of her mat in cm² ? (Take π = 3.14)

• 3925 cm²

• 7850 cm²

• 15 700 cm²

• 31 400 cm²

• 25π m²

• 6.25π m²

• 5π m²

• 1.25π m²