 | William Slocomb - 1828 - 160 pages
...inclose just 10 acres? Ans. 141,79+rods. PROS. 5. The diameter of a circle given, to find the area. Multiply the square of the diameter by ,7854. 1. What is the area of a circle whose diameter is 623? Ans. 304836,5+. 2. How many acres in a circular island, whose diameter is 124 rods? Ans. 75... | |
 | Euclid, Dionysius Lardner - Euclid's Elements - 1828 - 542 pages
...degree of approximation (634). The following practical rule may be derived from (634) and (636). • To find the area of a circle multiply the square of the radius by 31415, and divide the result by 10000.' This will give the area, subject to an error of less... | |
 | B[enjamin] Franklin Callender - Measurement - 1836 - 226 pages
...properties than any other geometrical figure. To find the area of a circle having the diameter given. Multiply the square of the diameter by .7854. 1. What is the area of a circle, the diameter of which is 25? 25X25=625X.7854=490.875 the area. If the circumference only be given,... | |
 | A. Turnbull - Arithmetic - 1836 - 368 pages
...but any t,f the above methods will give a result sufficiently correct fur all practical purposes. 6. To find the area of a circle, multiply the square of the diameter by .7854 ; or multiply half the circumference by half the diameter ; or multiply the circumference and diameter... | |
 | Mathematics - 1836 - 488 pages
...the number of degrees in the arc; so is the circumference of the circle, to the length of the arc. To find the area of a circle. Multiply the square of the diameter by the decimals .7854. Or, multiply half the diameter into half the circumference. Or, multiply the whole... | |
 | Roswell Chamberlain Smith - Arithmetic - 1841 - 324 pages
...square inscribed in a circle -.—Multiply the diameter by .707016. tr the circumference by .255079. 5. To find the area of a circle :— Multiply the square of the diameter by .785398, or tit* tquate of the circumference by .079577525. 6. Te lind the diameter of a elide:—... | |
 | Osman Call - Arithmetic - 1842 - 200 pages
...circumference of a circle to its diameter. THE DIAMETER OF A CIRCLE BEING GIVEN, TO FIND ITS AREA. RULE. — Multiply the square of the diameter by ,7854. 1. What is the area of a. circle, the diameter of which is 12? Ans. 113,0976. 2. What is the area of a circle, the diameter being 9 ?... | |
 | Roswell Chamberlain Smith - Arithmetic - 1842 - 320 pages
...inscribed in a circle : — Multiply the diameter by .707016, or the circumference by .2251)79. 5. To find the area of a circle -.—Multiply the square of the diameter by .785398, or the square of the circumference by .0711577525. 6. To Hud the diameter ofa circle: —... | |
 | Roswell Chamberlain Smith - Arithmetic - 1843 - 320 pages
...square inscribed in a circle;—Multiply the diameter by .707016, or the circumference by .225079. 5. To find the area of a circle -.—Multiply the square of the diameter by .785398, or tks tquare of the circumference by .079577525. 6. To find the diameter of a circle:—Multiply... | |
 | William Scott - Measurement - 1845 - 288 pages
...s=Ja*,' or, since d=2r, rfazz4r2: whence, by substitution, 1 : 4r2 :: ^ : s, .-. 8=тгг2. Consequently, to find the area of a circle, Multiply the square of the diameter of the circle by .7854: or Multiply the square of the radius of the circle by 3.1416 : the product... | |
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To find the area of a circle, multiply the square of the diameter by .7854. 
