How to change dimensions after constraining in CATIA V5 sketcher?

I am a beginner at CATIA and i need to draw the part in the given figure (Fig 4.73 and 4.74). I drew the sketch using the profile tool without dimensions and constrained it (in the second photo that I have attached). After that when I tried to dimension it, the sketch gets distorted. (See the orange line that is highlighted in the third photo).

What is the most accurate way to draw an iso constrained sketch? Should I dimension while sketching or can I dimension it later after applying constraints?
Please help me!
Thanks in advance :)

2 Answers

This is not catia problem. There is a problem on the example. You can not give 4mm while you are using 9mm and 5mm together. Because 9-5=4. You can not create a triangle which one of the edge and the hipotenus are 4mm at the same time. Not possible.

The dimensions are not right as Ozgur mentioned earlier. Also, if you ever face the problem of distortion of the sketch on constraining, just remove one constrain to turn it white, and manually make changes to bring it back to the natural position. Make sure that the dimensions are right and put them in in some other order. This helps.