If each side of a rectangle is increased by $50\%$, its area will increase by _____.

The length of a rectangle is twice its breadth. If the length is decreased by half of $10$ cm and the breadth is increased by half of $10$ cm, the area of the rectangle is increased by $5$ sq. cm more than $70$ sq. cm. Find the length of the rectangle.

Area of circle is equal to the area of a rectangle having a perimeter of $50$ cm and the length is more than its breadth by $3$ cm. What is the diameter of the circle?

In the figure given below, find $\angle \mathrm{QSR}:$

The area of a rectangle is $4$ times the area of a square. The length of the rectangle is $90$ cm and the breadth of the rectangle is $\frac{2}{3}$rd of the side of the square. What is the side of the square?

The difference between the circumference and diameter of a circle is $150$ m. The radius of that circle is:

Take: $\pi =\frac{22}{7}$

A square park has each side $50$ m. At each corner of the park, there is a flower bed in the form of a quadrant of radius $7$ m, as shown in the figure. Find the area of the remaining part of the park.