A question tells me to construct an angle using a ruler and a pair of compasses.

No idea how to do this without a protractor, any help?

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- Jun 5th 2010, 12:36 PMMukilabConstruct an angle
A question tells me to construct an angle using a ruler and a pair of compasses.

No idea how to do this without a protractor, any help? - Jun 5th 2010, 02:12 PMDeadstar
- Jun 6th 2010, 01:39 AMMukilab
Doesn't tell me how to create an angle using only a ruler and compass

- Jun 6th 2010, 04:10 AMMukilab
Any other help?

I've thought about this and I don't know how it can be feasibly possible without extensive working and no calculator.

Surely there must be some error because you can simply do this with a protractor and ruler. :( - Jun 6th 2010, 05:22 AMDeadstar
- Jun 6th 2010, 08:36 AMMukilab
I have a single line. From that single line I am supposed to construct an angle of 30 degrees.

- Jun 6th 2010, 08:52 AMDeadstar
How to construct (draw) a 30 degree angle with compass and straightedge or ruler - Math Open Reference

Or construct a equilateral triangle using the wiki link and figure out how to divide an angle in two...

These take a bit of time to explain so google is the best bet. - Jun 6th 2010, 09:12 AMMukilab
thanks, there are so many new things on that site. I wonder how these can be proved without measurement.

- Jun 6th 2010, 09:42 AMhungthinh92
Actually, if you want to find 30 degree angle with compass and ruler, you can do like this:

A. Draw an equilateral triangle:

Step 1:**Draw a random line.**

Step 2:**Put the point of your compass at one end of the segment and the pencil point at the other**.

Step 3:**Without moving the point of the compass and without changing how wide it is set, swing the compass in approximately a quarter-circle (up & away from the line segment)**.

Step 4:**Without changing how wide the compass is spread, move the compass point to the other end**.

Step 5:**Swing the compass so that the arc you are creating crosses the arc you drew in step 3**.

Step 6:**Mark the place where the two arcs cross.**

Step 7:**Using a ruler, draw line segments that connect the spot where the arcs cross to each end of the original line segment**.

B. Draw a height of the triangle.http://mathcentral.uregina.ca/QQ/dat...9.02/rosa2.gif