Copy Angles and Make Supplementary / Complementary Angles:

Step 1: Click on the angle that you want to copy.

Step 2: Click the "Copy Angle", "Make Supplementary Angle" or "Make Complementary Angle" button from the toolbar.

You can drag "x" to move and "o" to rotate the copied angles.

Copy Segment:

Step 1: Click on the segment that you want to copy.

Step 2: Click the "Copy Segment" button from the toolbar.

You can drag "x" to move and "o" to rotate the copied segment.

Copy Triangle:

Step 1: Double click any one vertex of the triangle.

Step 2: Click the other two vertices one by one.

Step 3: Click the "Make Congruent Triangle" or "Make Similar Triangle" button from the toolbar.

You can drag "o" to rotate and slide "^" horizontally to flip the copied triangle. Also you can use the slide to change the scale for similar triangle.