.
Calculate the area of the triangle ABC using the Heron's formula.
Then divide the area by the base length |CA| to get the altitude.
Do not forget the coefficient = 0.5 in the formula for the triangle area.
------------
On the Heron's formula, see the lessons
- Proof of the Heron's formula for the area of a triangle
- One more proof of the Heron's formula for the area of a triangle
- Solved problems on area of triangles
in this site.
Compare your problem and my proposed solution with the Problem 5 of the last lesson in this list.
Also, you have this free of charge online textbook on Geometry
GEOMETRY - YOUR ONLINE TEXTBOOK
in this site.
The referred lessons are the part of this online textbook under the topic "Area of triangles".
Save the link to this online textbook together with its description
Free of charge online textbook in GEOMETRY
https://www.algebra.com/algebra/homework/Triangles/GEOMETRY-your-online-textbook.lesson
to your archive and use it when it is needed.