 | Benjamin Greenleaf - Geometry - 1868 - 340 pages
...circle. 589. Cor. 1. The surface of a sphere is equal to the area of four of its great circles. For the area of a circle is equal to the product of the circumference by half the radius, or one fourth of the diameter (Prop. XV. Bk.YI.). 590. Cor. 2. The... | |
 | Eli Todd Tappan - Geometry - 1873 - 288 pages
...787. Corollary. — The area of the surface of a sphere is four times the area of a great circle. For the area of a circle is equal to the product of its circumference by one-fourth of the diameter. 788. Corollary — The area of the surface of a sphere is equal to the... | |
 | Benjamin Greenleaf - Geometry - 1873 - 202 pages
...circle. 362. Cor. 1. The surface of a sphere is equal to the area of four of its great circles. For the area of a circle is equal to the product of the circumference by half the radius, or one fourth of the diameter (Theo. XXXII. Bk. IV.). 363. Cor. 2.... | |
 | Benjamin Greenleaf - Geometry - 1874 - 206 pages
...squares of their radii (Theo. XXX.) ; therefore Sector ACB: Sector DOE : : R* : r\ THEOREM XXXII. 242. The. area of a circle is equal to the product of the circumference by half the radius. Let C denote the circumference of the circle, whose center is O,... | |
 | Aaron Schuyler - Geometry - 1876 - 384 pages
...But, =-, C C' C' C' A 7But, .^ = -75 , (308), .- . 7 = -73 • 310. Proposition XXIII.— Theorem. The area of a circle is equal to the product of its circumference by one-half of its radius. Let r denote the radius of the circle ; c, its circumference ; C, its area... | |
 | Samuel H. Winter - 1877 - 452 pages
...distance from A to B being 100 yards. Find the distance BC, and the height of the pole. 14. Prove that the area of a circle is equal to the product of its semi-circumference by its radius. Three circles, each of radius 1 foot, touch one another externally.... | |
 | 1894 - 834 pages
...by a quantity less than any that *• scribed about the sphere.* He also gave the first proof that the area of a circle is equal to the product of the circumference and the radius, determined the area of an ellipse, and proved that the area of any segment... | |
 | Vermont. Dept. of Education - 1880 - 216 pages
...squares of those lines." Prove, " The diagonal and side of a square have no common measure '' 7. Prove, "The area of a circle is equal to the product of its circumference by half the radius " 8. Define, polyedron, right prism, parallelepiped, pyramid, sphere, zone. 9. I)raw the figures to... | |
 | Sandhurst roy. military coll - 1880 - 68 pages
...distance from A to B being 100 yards. Find the distance BC, and the height of the pole. 14. Prove that the area of a circle is equal to the product of its semicircumference by its radius. Three circles, each of radius 1 foot, touch one another externally.... | |
 | Albert Taylor Bledsoe - Mathematics - 1886 - 253 pages
...indeterminates to some examples. " For a second example/' * says the author, " let us propose to prove that the area of a circle is equal to the product of its circumference by the half of its radius ; that is to say, denoting the radius by E, the ratio of the circumference to... | |
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The area of a circle is equal to the product of its circumference by half the radius.* Let ACDE be a circle whose centre is O and radius OA : then will area OA— ^OAxcirc. 
