Answer:
The area of the circle is 
Step-by-step explanation:
we know that
The area of a circle subtends a central angle of
radians
so
By proportion find the area of the circle

Answer:
B, C
Step-by-step explanation:
Both these intervals are where the graph is increasing.
Answer:
70
Step-by-step explanation:
add 19 twice and 16 twice to get your answer.
81=81•2/2=162/2
81 1/2=162/2+1/2
=163/2
So 81 1/2=163/2=81.5