Help a friend in need

a) 4.71ft

b) 3.53ft^2

Step-by-step explanation:

Perimeter is 1/2 the circumference

1/2 Circumference = 2*pi*radius

Radius = 1/2 Diameter

Radius = 3/2 = 1.5ft

Circumference = 2*pi*1.5ft = 9.42

1/2 Circumference = 4.71

4.71ft is the perimeter.

The area is 1/2 that of a full circle

A = pi*r^2

A = 3.14*1.5*1.5

A = 7.065ft^2

1/2 A = 3.53ft^2

hope it you

step-by-step explanation:

sin(7pi/6 - pi/3)  

= sin(7pi/6 - 2pi/6)  

= sin(5pi/6)  

= sin(pi - pi/6)  

= sin(pi/6)  

= 1/2  

sin 7pi/6 - sin pi/3  

= sin (pi + pi/6) - sin pi/3  

= -sin pi/6 - sin pi/3  

= -1/2 - sqrt(3)/2  

= -(1+sqrt(3))2