Q&A for How to Find the Area of a Semicircle

Multiply pi by the square of the radius.

Yes, PEMDAS has to be used because of the exponentiation, you have to do that first. If you rewrite it as π×r×r/2 then you don't have to worry about PEMDAS, because it involves only multiplication and division.

Given a radius of circle = 1.4m. As we know, the area of semicircle=((pie)*r*r)/2=(3.14*1.4*1.4)/(2)=3.078 m square.

This question uses the concept of circumference rather than area, so be sure to read about calculating the circumference of a circle. To find the radius from the perimeter, you need to know that the perimeter (also called "circumference" when talking about a full circle) of a full circle is given by 2*pi*r. Since we need the perimeter of a semicircle instead of a full circle, divide this by 2 (since the arc length is half) but then add the diameter, which is two times the radius (to account for the straight part across the bottom). So, perimeter of semicircle = (2*pi*r)/2 + 2r = (2 + pi)r. Solve for r = perimeter / (2 + pi), and you have your radius!

Because "semi" means "half."

If you're asking about the circumference of a semicircle (the length of the arc), a full circle's circumference is pi multiplied by the diameter, so a semicircle's circumference would be half that.

First multiply the area by 2. Then divide by pi. Then take the square root. Then double that number and you get the diameter in meters.

If you don't know the radius, diameter, or circumference, you can't find the area.

The area of a circle is πr², where r is the radius of the circle. The area of half the semicircle is one-quarter of that.

If the values you gave are the measurements of the sides, you just need to add them.

The diameter is twice the radius. It's also the circumference divided by pi.

If you're referring to a semicircle, double the arc length, then divide by twice pi (π x 2).

To find the diameter, multiply the radius by two and you should get the diameter and that is the length.

Assuming the "perimeter" consists of only the curved side of the park, the circumference of the full circle would be 144. Divide that by pi to get a diameter of 45.84. The radius is half the diameter, or 22.92 m. The area is πr², or 1,650.36 square meters.

You double the arc, then divide by pi to get the diameter, and divide again by 2 to get the radius. (It's quicker to divide the full-circle circumference by twice pi, or 6.28.)

The radius would be 6π, so the area of the full circle would be π(6π)² = 36π³, and the area of the semicircle would be 18π³.

To find the radius, you just need to know the diameter of the semicircle. The area is not needed.

For the area of a semicircle we use the formula: (π * r^2) / 2 for a given radius r. Because the diameter is half the radius, we can make the conversion r = d / 2, which gives us the following: (π * (d / 2)^2) / 2, which when simplified will give us (π * d^2) / 8. Therefore the formula for the area of a semicircle in terms of its diameter is (π * d^2) / 8 for diameter d.

The formula for area of a semicircle is πr²/2. π55²/2 = π3025/2 = 9498.5/2 = 4749.25 cm.

The radius is 1.3 m. Square that, multiply by pi, then divide by 2.

Find the area of the full circle (πr²) and divide by 2.

Area of a semicircle = πr² / 2 = (3.14)(36) / 2 = 56.52 square centimeters.

That is the formula for the circumference of a circle.

V = πr²h, where r is the radius and h is the height or length of the cylinder.

You would need to know the radius of the circle. Then using A=πr², find the area of the full circle. Divide that by 4 to find the area of 1/4 of the circle. Then multiply that by 3 to find the area of 3/4 of the circle.

If the diameter is d, the radius is d/2. The area of the semicircle is (πr²) / 2 = [(π)(d/2)²] / 2 = [(π)(d²/4)] / 2.

If we assume the 28 cm refers to the radius, then the area of the semicircle is [(π)(r²)] / 2 = [22/7)(28)²] / 2 = 1,232 square centimeters.

You would need to know two radii, one for the semicircle and one for the circle. You'd then calculate the two areas and subtract the circle's area from the semicircle's area.

Double the radius to get the diameter. Multiply by pi to get the circumference of the full circle. Divide by 2 to get the circumference of the semicircle.

If r = 56, A = (πr²) / 2 = [(22/7)(3136)] / 2 = 4928.