Triangle Classification: Identifying an Acute-Angled Triangle from Diagram

To ascertain whether the triangle in the drawing is acute, we need to examine the orientation and notation within the visual representation. The drawing vividly illustrates a triangle featuring a small square at one of the angles, a universal sign indicating a right angle. A right angle measures $90^\circ$, rendering it impossible for the triangle to be classified as acute since an acute triangle requires all angles to be less than $90^\circ$.

Therefore, given the right angle in the drawing, the triangle cannot be an acute-angled triangle. Consequently, the correct choice is:

No (:

No