Has any1 done Construction in geometry? We have to make a regular octagon with compass + straightegde.?

Question

you cannot measure anything. you have to make it with all arcs and lines. i think it has something to do with triangles but idk. if you can't answer this, just tell me how many degrees a regular octagon has intotal?

Answer 1

First make a circle with your compass. Draw a straight line though the center, all the way across the circle. Erect a perpendicular to this line and extend the perpendicular completely through the circle, giving you four 90-degree angles. Now bisect any two adjacent 90-degree angles, giving you 45-degree angles. Extend the bisections to the far side of the circle, dividing it into eight sections. Then draw a line from the points where two adjacent bisections intersect the circle. Finally, repeat this last step, all the way around the circle, resulting in an eight-sided figure--a regular octagon.

Answer 2

A regular N sided figure has internal angle degrees of (n-2)180/n
So an octagon (8 sides) has 6 x 180/8 internal degrees. Since there are 8 angles at 135 each the interior angles sum to 1,080 degrees.

Answer 3

I'll give you a bit of hint. Use the Octagon's inscribing circle. Divide the circle into 8 equal arcs using two perpendicular diameter lines and...

Answer 4

A regular octagon has 8 sides so the internal angles between the sides are 135 degrees

http://www.cyffredin.co.uk/Books%20on%20the%20Blackboard.htm

shows a method using a book - maybe you can adapt it?

Answer 5

720

Answer 6

your making it more dificult than it needs to be

try making 8 evenly placed points then connecting them with strait lines you should be able to do this with strait lines using the compass to keep a central point