Below are the steps.
Draw a triangle ABC. Measure the angles CBA and BAC.
For the congruent triangle-
Draw segment DE with length as 'a' using Segment with Given Length tool.
DE is same as BC.
Using Angle with Given Size tool, click on point D and then click on point E(DEE').
Select Clockwise radio button in Angle with Given Size text box,
and delete 45 degrees from the text field.
Select angle as alpha using the Symbols table seen as alpha in the text field.
Click on OK in the box.
Using Segment with Given Lengthtool, click on D and put length as c.
DF is same as AB.
Draw a circle with center D and radius DF.
Using Segment with given size tool, click onE, put length as b.
EG is same as AC.
Draw a circle with center E and radius EG.
Two circles intersect, mark point on intersection as H.
Now Join points D, H and H,E.
Using the Angle with Given Size tool, click on point E and then on point H.
In the Angle text box, select beta from Symbols. Select Clockwise radio button.
Click OK in the box.
We get the required triangle.
Assignment answer figure is shown at 14.26 min in the video.