posted by kelly on .
please can some one help me..?
Part a -
O is the centre of the circle, and P , Q are points on the
circumference of the circle, with the angle POQ being a right angle. The radius of the circle is 3 cm.
Choose the option that is the area of the smaller sector POQ, correct to 3 decimal places.
Options - A) 7.065 cm^2 B) 7.069 cm^2 C) 7.071 cm^2
D) 10.07 cm^2
Choose the option that is the perimeter of the smaller sector POQ, correct to 3 significant figures. (The perimeter of the sector is the distance around all the edges of the sector.)
Options - A) 7.069 cm B) 7.07 cm C) 10.7 cm D) 10.712 cm
for part a i thinks its 7.069cm squred
but i don't knw what part b is
I got a different answer for Part a. I first figured the area of the complete circle [A = pi(r^2)]. Then I found one fourth of the complete area.
For Part b, you first need the total circumference of the circle. Using the formula C = pi (2r), I get 18.8496 cm. One "side" of the sector then is 18.84/4 = 4.7124.
Add 4.7124 to the other two sides of the sector to find the total perimeter.