Problem 1: Radius of a circle is 14cm. and the angle at centre formed by a sector is 45 degrees. Find the area of the sector?

Solution:

Area of a sector =

=77

Problem 2: A rectangular sheet of 30 m × 20 m dimension is cut from its each corner as quadrant of radius 3.5m. Find the area of remaining portion ?

Solution:

4 sectors = 1 circle

Area of rectangle = 30*20=600

600-38.5= 561.5

Problem 3: Smaller diagonal of a rhombus is equal to length of its sides. If length of each side is 4 cm, then what is the area (in cm2) of an equilateral triangle with side equal to the bigger diagonal of the rhombus?

Solution:

Area of equilateral triangle =