生成该题的解题讲解视频---**Question 2** **Question Stem:** 2. 若某正三棱锥的底面边长为 a, 侧面都是等腰直角三角形, 求该正三棱锥的表面积. (If a regular triangular pyramid has base side length a, and all lateral faces are isosceles right triangles, find the surface area of this regular triangular pyramid.) **Other Relevant Text/Formulas in the image (potentially related to Q2):** * S_底 = 1/2 * a * sqrt(3)/2 * a = sqrt(3)/4 * a^2 * S_侧 = 1/2 * (sqrt(2)/2 * a)^2 * 3 * S_侧 = 1/2 * 1/2 * a^2 * 3 **Chart/Diagram Description:** * **Type:** 3D representation of a triangular pyramid. * **Main Elements:** The diagram depicts a pyramid with a triangular base. Lines connect the vertices of the base to a single apex above the base. Lines from the apex to the midpoints of the base sides are also shown, representing the slant heights. A vertical line is drawn from the apex to the center of the base, representing the height of the pyramid. The base triangle appears to be equilateral (as it's a regular triangular pyramid). * **Labels and Annotations:** No clear numerical or letter labels are visible on the diagram itself. There are some faint red scribbles within the base triangle.