Answer:

Step-by-step explanation:
GIVEN: A square with base
, a circle that perfectly fits inside square.
TO FIND: Approximate area of circle.
SOLUTION:
Consider the figure attached.
let the radius of circle be 
radius of circle 


Area of circle 


Hence the area of circle that perfectly fits inside the square is 
Answer:
21
Step-by-step explanation:
Try using this notation: a(n) and not an.
an=n^3-2n becomes a(n) = n^3 - 2n.
Then a(1) = 1^3 - 2(1) = 1 - 2 = -1
a(2) = 2^3 - 2(2) = 8 - 4 = 4
a(3) = 3^3 - 2(3) = 27 - 6 = 21
(8•40) + (8•5) = 320 + 40 = 360