So here, ABCD is being inscribed in a circle, so ABCD is a cyclic quadrilateral (as inscribed in a circle) also, there exists a property of cyclic quadrilateral, i.e, the sum of opposite angles of a cyclic quadrilateral is 180°, so we can just write the following equation using this :




Answer: 
Step-by-step explanation:
We know that the circumference of a circle is given by :-
, where r is the radius of the circle .
Given : Circumference of circle = 16 cm
Then, 
i.e
(1)
We know that the area of circle is given by :-

i.e.
[From (1)]
i.e.
i.e.
Put 
Hence, area of circle = 
Answer:

Step by step explanation:
![\text{Given that, two roots are}~ -4~ \text{and}~ 4i.\\\\\text{Let,}\\\\~~~~~~~x = 4i\\\\\implies x^2 = 16i^2~~~~~~~;[\text{Square on both sides}]\\\\\implies x^2 = -16~~~~~~~~;[i^2 = -1]\\\\\implies x^2 +16 = 0\\\\\text{So,}~ x^2 +16~ \text{ is a factor of the 3 degree polynomial}.\\ \\ \text{The polynomial is ,}\\\\ f(x) = (x+4)(x^2 +16)\\\\~~~~~~~=x^3 +16x +4x^2 +64\\\\~~~~~~~=x^3 +4x^2 +16x +64](https://tex.z-dn.net/?f=%5Ctext%7BGiven%20that%2C%20%20two%20roots%20are%7D~%20-4~%20%5Ctext%7Band%7D~%20%204i.%5C%5C%5C%5C%5Ctext%7BLet%2C%7D%5C%5C%5C%5C~~~~~~~x%20%3D%204i%5C%5C%5C%5C%5Cimplies%20%20x%5E2%20%3D%2016i%5E2~~~~~~~%3B%5B%5Ctext%7BSquare%20on%20both%20sides%7D%5D%5C%5C%5C%5C%5Cimplies%20x%5E2%20%3D%20-16~~~~~~~~%3B%5Bi%5E2%20%3D%20-1%5D%5C%5C%5C%5C%5Cimplies%20x%5E2%20%2B16%20%3D%200%5C%5C%5C%5C%5Ctext%7BSo%2C%7D~%20x%5E2%20%2B16~%20%5Ctext%7B%20is%20a%20factor%20of%20the%203%20degree%20polynomial%7D.%5C%5C%20%5C%5C%20%5Ctext%7BThe%20polynomial%20is%20%2C%7D%5C%5C%5C%5C%20f%28x%29%20%3D%20%28x%2B4%29%28x%5E2%20%2B16%29%5C%5C%5C%5C~~~~~~~%3Dx%5E3%20%2B16x%20%2B4x%5E2%20%2B64%5C%5C%5C%5C~~~~~~~%3Dx%5E3%20%2B4x%5E2%20%2B16x%20%2B64)
Answer:
The artifact was made approximately 13,306 years ago
Step-by-step explanation:
The half-life of Carbon-14 = 5730 years
The formula for radioactive decay is given by the equation:

The amount of Carbon-14 left = 20% = 20/100 = 0.2


t ≈ 13,306 years