The area of a semicircle of radius 4r is

The area of a square is 100 cm². The circumference (in cm) of the largest circle cut of it is

If the radius of a circle is tripled, the area becomes

Fill in the blanks to make the statements true.

Perimeter of a regular polygon = length of one side × ___________.

Fill in the blanks to make the statements true.

If a wire in the shape of a square is rebent into a rectangle, then the________ of both shapes remain same, but _______ may vary.