NCERT · Class 10 · Mathematics · Surface Areas and VolumesThe slant height ($l$) of a cone with radius $r$ and height $h$ is given by:
Step-by-Step Solution
By applying Pythagoras theorem to the right-angled triangle formed by radius, height, and slant height of a cone, we get $l = \sqrt{r^2 + h^2}$.
Detailed Options Breakdown
Option : $r + h$
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Surface Areas and Volumes.
Option 1: $\sqrt{r^2 - h^2}$
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Surface Areas and Volumes.
Option 2: $\sqrt{r^2 + h^2}$ (Correct Answer)
Correct choice. Refer to the step-by-step verified solution guidelines above for details.
Option 3: $r^2 + h^2$
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Surface Areas and Volumes.
💡 Study Guide: This question tests core syllabus concepts from Surface Areas and Volumes. For formulas, key summaries, and mock exam reference guides, read the full Surface Areas and Volumes Revision Notes.