Geometry/constructions

Question

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?

Given two non-parallel lines, the locus of points that are equidistant to those lines is the angle bisector between those lines — Arthur, Mar 16 '17 at 14:22

Aman Singh · Answer 1 · 2017-03-18T03:17:25.763

0

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!

edited Mar 18 '17 at 03:17

answered Mar 16 '17 at 17:27

Aman Singh

1

We know point C precisely, because AC = 8 and we know the angle A? Then we can draw the segment BC. So we can bisect the angle ABC? – Eirik Mar 16 '17 at 22:38
Well first of all tell me is the shape name ABCD or ABDC? – Aman Singh Mar 17 '17 at 08:51
ABCD, A left vertex, B right vertex, C right upper vertex and D, left upper vertex. – Eirik Mar 18 '17 at 00:09
Okay the angle at A is the angle AC makes with AB then... – Aman Singh Mar 18 '17 at 03:04
Then it's simple.... Just draw parallel through C which is parallel to AB and then bisect AB and BC. The point where two lines will meet is point D – Aman Singh Mar 18 '17 at 03:08
To bisect the angle refer www.mathopenref.com/constbisectangle.html – Aman Singh Mar 18 '17 at 03:10
I thought the angle at A was the angle which AD made with AB – Aman Singh Mar 18 '17 at 03:11

Geometry/constructions

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