...1. 90 degrees is exactly a quarter of a whole circle . 2. The area of a circle with a radius of 8 inches is Area = πR² = π * ...

2 Answers · Science & Mathematics · 30/09/2009

http://www.schoolphysics.co.uk/age16-19/Electricity%20and%20magnetism/Electromagnetic%20induction/text/Rotating_disc_and_generators/index.html

1 Answers · Science & Mathematics · 23/03/2015

60 degrees is 1/6

**of**360 degrees (i.e. the whole**circle**.)**Area of sector**= 4.72 cm^2**Area of circle**= 4.72cm^2 * 6 = 28.32**Area of circle**...2 Answers · Science & Mathematics · 04/08/2009

...24 cm Length

**of**the arc = 38 cm - 24 cm = 14 cm Let angle**of**the**sector**= theta theta = length**of**arc/radius theta = 14/12 rad theta = 7/6 rad If angle is 2*PI rad, then**area**= Pi * r^2 (where r = radius) Angle = 7/6 rad. Therefore...2 Answers · Science & Mathematics · 20/07/2009

...radius be r and the angle subtended by the

**sector**at the centre**of**the**circle**be**a**in radian measure**a**= 7/r The**area of**the**sector**is (r^2)***a**/2 = 3, so**a**= 6/r^2 The perimeter**of**the**sector**...1 Answers · Science & Mathematics · 06/09/2011

...

**a**measure**of**arc equal to 360 degrees we can see that the this**sector**is 90/360=1/4 the**area of a circle**with radius r as described by the above equation. Thus, the**area of**...3 Answers · Science & Mathematics · 29/11/2012

...radius of 10 then its area is found by A = πr². A = π(10)² = 100π, so this is the area of the entire circle . Since the area of the sector is only 40π, that is 40π/100π or 40% of the circle . 40% of the circle ...

4 Answers · Science & Mathematics · 28/09/2007

0.3pi*r^2. Think about it. If the arc measures 1

**circle**= 2pi, the**area**= pi*r^2. If it measures 3/5*pi, that's 0.3**of a circle**and**area**= 0.3pi*r*2.3 Answers · Science & Mathematics · 09/05/2010

...answer is right for wrong reason. If r not = 1 that formula doesn't work.

**Area of circle**= pi*r^2**Area of**quarter**circle**= pi*r^2/4 = 0.785 ft^2 When r...2 Answers · Science & Mathematics · 28/09/2007

**A**= (1/2)r^2.w where w is the**sector**angle in radians. dA/dt = rw.dr/dt = 6 x 0.42.pi x 0.3 = 2.38 cm^2/s2 Answers · Science & Mathematics · 27/02/2010