Half an octagon has five sides is it is divided in two by a line joining opposite vertices. It has six sides in the dividing line joins the midpoints of opposite sides.
You can only do this for a regular octagon. It is much easier to understand the method if you do a rough sketch and follow the explanation using that. Unfortunately, this browser does not support any kind of drawing! Suppose the diameter of the octagon is D. Therefore the diameter of the circumscribing circle is also D. Form the centre of this circle, draw lines to two adjacent vertices of the octagon. The lengths of these lines is D/2 because these are radii of the circle. These lines and the side of the octagon form an isosceles triangle, and the apothem is the height of this triangle. Now consider half this triangle: the right angled triangle formed by the apothem, half the side of the octagon and the radius. The angles at the apex of the octagon is 360/8 = 45 degrees. So the angle at the apex of the right angled triangle is half that = 22.5 degrees. Then cos(22.5 deg) = Apothem/Radius So that Apothem = Radius*cos(22.5 deg) = D/2*0.9239 (approx).
An octagon has 8 angles.An octagon has 8 angles.An octagon has 8 angles.An octagon has 8 angles.
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an octagon...
Half an octagon has five sides is it is divided in two by a line joining opposite vertices. It has six sides in the dividing line joins the midpoints of opposite sides.
We know that an octagon is an eight-side polygon. Since each side has the same distance form the center of the circumscribed circle of the octagon, this octagon is a regular octagon. If we draw the radii of the circle (their endpoints there are at the vertexes of the octagon), we form 8 isosceles triangle, which radius represents two their congruent sides with a measure of 7.5 cm, and the distance drawn from the center of the circle to the sides of the octagon represents their altitudes with a measure of 6.9 cm. So, by using the Pythagorean theorem we can find the half of the side of the octagon, which is: 7.5)^2 - (6.9)^2 = 8.64 Since one half of the octagon side is square root of 8.64, the whole side is 2(square root of 8.64) Thus the perimeter of this octagon is approximately 47 cm [8 x 2(square root of 8.64)].
whatz the value of a 1857 California Gold Octagonal Half Dollar and how much does it weigh ....?
whatz the value of a 1857 California Gold Octagonal Half Dollar and how much does it weigh ....?
six
You can only do this for a regular octagon. It is much easier to understand the method if you do a rough sketch and follow the explanation using that. Unfortunately, this browser does not support any kind of drawing! Suppose the diameter of the octagon is D. Therefore the diameter of the circumscribing circle is also D. Form the centre of this circle, draw lines to two adjacent vertices of the octagon. The lengths of these lines is D/2 because these are radii of the circle. These lines and the side of the octagon form an isosceles triangle, and the apothem is the height of this triangle. Now consider half this triangle: the right angled triangle formed by the apothem, half the side of the octagon and the radius. The angles at the apex of the octagon is 360/8 = 45 degrees. So the angle at the apex of the right angled triangle is half that = 22.5 degrees. Then cos(22.5 deg) = Apothem/Radius So that Apothem = Radius*cos(22.5 deg) = D/2*0.9239 (approx).
An octagon has 8 angles.An octagon has 8 angles.An octagon has 8 angles.An octagon has 8 angles.
Need to know who made it, what type of finish, current condition, accessories, box, papers, etc..
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an octagon...
No, but an octagon is.
An octagon-based prism.An octagon-based prism.An octagon-based prism.An octagon-based prism.