SSC Steno Grade C and D 8 Aug 2025 Shift 3 Paper

Concept:The figure is a triangle subdivided by lines from the base to the opposite vertex. The number of such triangles can be counted directly or using a formula when the base is divided into equal segments.Explanation:Count all triangles of different sizes formed by the internal lines.Alternatively, use the formula: Number of triangles = $\frac{n(n+2)(2n+1)}{8}$, where $n$ is the number of small triangles along the base.Here, the base has 4 small triangles, so $n=4$.Substitute: $\frac{4 \times (4+2) \times (2\times4+1)}{8} = \frac{4 \times 6 \times 9}{8} = 27$.Thus, the figure contains 27 triangles in total.Answer:Option A. 27