The question involves understanding the path of a light ray passing through an equilateral glass prism. Here, we need to determine which diagram accurately shows the light's path through the prism. Let's break down the process:

1. The light ray enters the prism at a face, making an incident angle with the normal.
2. Refraction occurs at the entrance because the speed of light changes as it moves from air (or vacuum) into glass, affecting the ray's direction according to Snell's Law: \(n_1 \sin \theta_1 = n_2 \sin \theta_2\), where \(n_1\) and \(n_2\) are the refractive indices of air and glass respectively, and \(\theta_1\) and \(\theta_2\) are the angles of incidence and refraction.
3. After refraction through the first surface, the light travels across the prism and approaches the second face.
4. At the second face, another refraction occurs as the light exits the prism back into the air. The light again changes direction according to Snell's Law.
5. For an equilateral prism with equal angles, the ray inside typically bends towards the base of the prism and, upon exiting, bends away from the normal.

Given these steps, the correct diagram of the path will show the light ray bending towards the base inside the prism and bending away upon exiting. This process is accurately displayed in the third option.

Hence, the correct diagram illustrating the path of the light ray through the glass prism is the third option.