Right Triangle Identification: Analyzing Triangle Properties Using Visual Geometry

Is the triangle in the drawing a right triangle?

To determine if the triangle in the drawing is a right triangle, we will look for direct visual indications. One common indication of a right triangle in drawings is a small square located at the vertex of the angle within the triangle, which signifies a $90^\circ$ angle.

After examining the provided drawing, a square marker is visible at one of the triangle's vertices. This symbol universally denotes that the angle at this vertex is a right angle.

Therefore, given the presence of this square, the triangle in the drawing is indeed a right triangle.

Thus, the correct conclusion is $\text{Yes}$.