Question

Find the area of a semi-circle with diameter 28m. Round to the nearest tenth

Answer 1

Answer:

307.7 m²

Explanation:

The area of a semi-circle of radius r can be calculated as:

$A=\frac{3.14\times r^2}{2}$

Then, the radius of a circle is half the diameter, so, the radius of the circle with a diameter of 28 m is:

$\text{radius}=\frac{\text{Diameter}}{2}=\frac{28\text{ m}}{2}=14\text{ m}$

Now, we can replace r by 14 m and get that the area of the semi-circle is:

$\begin{gathered} A=\frac{3.14\times(14m)^2}{2} \\ A=\frac{3.14\times196m^2}{2} \\ A=\frac{615.44m^2}{2} \\ A=307.7m^2 \end{gathered}$

Therefore, the area of the semi-circle with a diameter of 28m is 307.7 m²