The following is part of a quilt design. The shaded part is formed by five identical 3 units by 3 units squares. Calculate the length of the diameter of the circle.
The formula for diameter is d = 2√Area/pi. --> area of a circle is a = pi(r)^2. Would the radius be 3, 4.5, or 6?
The picture is here: http://warcount.googlepages.com/square.JPG
2007-01-27 00:19:43 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
You can see that a diameter is formed by the diagonal of a rectangle made from three squares in a row. If each square is 3 units on a side, the large rectangle is 3 units by 9 units. By the Pythagorean theorem, the diagonal of that rectangle is sqrt(3^2 + 9^2) = sqrt(9 + 81) = sqrt(90) = 3*sqrt(10). That's also the diameter, making the radius 1.5*sqrt(10) ~= 4.74. So it's about 4.5, but not exactly.
2007-01-27 00:28:19 · answer #1 · answered by DavidK93 7 · 0⤊ 0⤋
In the morning I had replied the first part of your question .Now that you have given the website address.I could see the design and the answer is that the radius of the circle would be 4.743 cm and hence the dia is 9.486 cm.The center of the circle would be at the intersection of the two straight lines drawn from the middle of the vertical and the horizontal cubes.
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2007-01-27 10:50:03 · answer #2 · answered by alpha 7 · 0⤊ 0⤋