Step 1: Understanding angle types
- A right angle is an angle that measures exactly $90^\circ$
- It is formed when two lines intersect to form a perfect L-shape
Step 2: Evaluating the options
(A) $90^\circ$ $\Rightarrow$ This is the correct and exact measure of a right angle
(B) $45^\circ$ $\Rightarrow$ This is an acute angle, less than a right angle
(C) $60^\circ$ $\Rightarrow$ Also an acute angle
(D) $120^\circ$ $\Rightarrow$ An obtuse angle, more than a right angle
\[
\boxed{\text{Correct Answer: (A) } 90^\circ}
\]
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.