Step 1: Understanding angle types
Angles are categorized based on their measurement in degrees:
- Acute angle $<$ 90°
- Right angle = 90°
- Obtuse angle $>$ 90° but $<$ 180°
- Straight angle = 180°
- Reflex angle $>$ 180° but $<$ 360°
- Whole angle = full turn
Step 2: What is a whole angle?
A whole angle is one complete rotation starting from a ray, making a full circle and coming back to its initial position.
This forms a complete revolution and is measured as:
Whole angle = $360^\circ$
\[
\boxed{\text{Correct Answer: (D) } 360^\circ}
\]
Find the unknown frequency if 24 is the median of the following frequency distribution:
\[\begin{array}{|c|c|c|c|c|c|} \hline \text{Class-interval} & 0-10 & 10-20 & 20-30 & 30-40 & 40-50 \\ \hline \text{Frequency} & 5 & 25 & 25 & \text{$p$} & 7 \\ \hline \end{array}\]
Two concentric circles are of radii $8\ \text{cm}$ and $5\ \text{cm}$. Find the length of the chord of the larger circle which touches (is tangent to) the smaller circle.