The area of a sector of a circle of radius $5 \, cm$,formed by an arc of length $3.5 \, cm$,is ..... $cm^2$.

The radius and vertical height of a cone are $5 \text{ cm}$ and $12 \text{ cm}$ respectively. Then its lateral surface area is? (in $\text{cm}^2$)

The area of a triangular lawn is $1600 \, m^{2}$. If one side is $64 \, m$ long and the other two sides are equal in length,the length of each equal side is......$m$

The base of a triangular field is three times its height. If the cost of cultivating the field at ₹ $36.72$ per hectare is ₹ $495.72$,then find its base and height.

$A$ room is $7 \text{ m}$ long and $5 \text{ m}$ broad. The doors and windows occupy $5 \text{ m}^2$. The cost of papering the remaining part of the walls with paper $75 \text{ cm}$ wide,at ₹ $4.20$ per piece of $13 \text{ m}$ length,is ₹ $39.20$. Find the height of the room in $\text{cm}$.

$A$ circular swimming pool is surrounded by a concrete wall $4 \ m$ wide. If the area of the concrete wall surrounding the pool is $11/25$ that of the pool,then the radius (in $m$) of the pool is