How do you do these problems???
What is the radius of a circle that its area is 254.5 square inches???
What is the diameter of a circle if its area is 132.7 square meters??
I don't understand this because of the thing that says "square"
area of circle = pi(r^2)
so for the first one :
254.5 = pi(r^2), divide both sides by pi
81 = r^2 , now take the square root of both sides
9 = r
do the second one the same way, double the answer you get for r to get the diameter.
For an explanation of "square" in a circle, check this site.
http://www.mathgoodies.com/lessons/vol2/circle_area.html
To solve these problems, you need to understand the formulas for the area and diameter of a circle.
The formula for the area of a circle is A = πr^2, where A represents the area and r represents the radius.
To find the radius when given the area, you can rearrange the formula as follows:
r = √(A/π)
1. For the first problem, where the area is 254.5 square inches:
- Substitute the given area (254.5) into the formula: r = √(254.5/π).
- Calculate the result by dividing 254.5 by π (approximately 3.14159). This gives you the approximate value of the radius.
2. For the second problem, where the area is 132.7 square meters:
- Follow the same steps as before: r = √(132.7/π).
- Again, divide 132.7 by π to find the approximate value of the radius.
Next, to find the diameter when given the area, you can use the formula for the diameter:
d = 2r
To find the diameter, substitute the calculated value of the radius into the formula.
By using the formulas and solving step-by-step, you'll be able to determine the radius and diameter of a circle given the area.