Geometry/constructions

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I want to contruct a trapes and I am finding it hard to find the last point D.

1) Construct a segment AB = 6.8 cm 2) Construct an angle at 67,5 degrees at A. 3) Construct AC = 8 cm 4) CD is parallell to AB 5) The distance between D and AB is equal to the distance between D and BC

Problem: 5) Well, I need a referance point on the segments AB and BC, dont I?

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As you say the angle at A is angle CAB not angle DAB.... Then...

Point C Is known to us.

Draw a parallel through C which is parallel to AB.

Now bisect angle ABC. We do this because first the point D is equidistant from AB and BC... So by locus theorem it will lie on bisector of AB and BC. And AB is parallel CD so D must also lie on parallel through C.

To bisect an angle, refer website

www.mathopenref.com/constbisectangle.html

The point where the parallel and bisector will meet is the point D.

Good day!