How to make right angled lines

Long time ago (29 years ago) I started to make all the drawings of my house in Autocad Light.

Half a year ago I recovered LibreCad, a lightweigth program with enough features for me, but some things take time to learn.


Two questions:
- I have an angled line. From the endpoint I want to draw a second line right angled to the first.
- I have an angled line. From a point in the neighbour I want to draw right angled line to the first.

How can I do that in a simple way?

line -> orthogonal
click the base line, then put the new line in place.

later you may have to short/extend it

HTH
Pere