Answer:
squr. 39
Explanation:
See attached graph.
Form a right triangles and determine the length of the two sides (BC and AC). Then calculate the hypotenuse (AB) with the Pythagorean Theorem.
AB = 13
I'm not sure what "squr.3AB really means. 3AB is 39. The square root of 39 is 6.4, if square root is what is meant.