Question

Help me pls desperate please plspls

Answer 1

Answer:

To the nearest whole number : 628

Step-by-step explanation:

The formula for the area of a circle is :

To work out the area you would first need to work out the radius. You can do this by dividing the diameter of 40 cm by 2, this gives you 20 cm. This is because the radius is half of the diameter.

Now that we have worked out the radius, the next step would be to work out the area. You can do this by multiplying pi by the radius of 20 squared, this gives you 1256.64.

The final step is to work out the area of this semi-circle. You can do this by dividing the area of 1256.64 by 2, this gives you 628.32 . This is because a semi-circle is half of a circle.

1) Divide 40 by 2.

2) Multiply pi by 20 squared.

3) Divide 1256.64 by 2.

Answer 2

Area of semi circle = π r²/2

= π 20 × 20 / 2

= 200 π

= 628 cm² (approx)