4. A regular hexagon ABCDEF is inscribed in a circle of diameter 16 cm. The point G is on the line FC, angle CGD = 90° and DG = 6.93 cm. (b) Find the perimeter of quadrilateral ABCF.
(c) Find the area of the quadrilateral ABCF.
(d) Find the area of the shaded region. (blue parts)
thank you!!​

The rate of decay of a radioactive substance depends upon the amount present initially. the mass y (mg) of the radioactive substance cobalt-60 present in a sample at time t (years) is represented by the exponential equation y=50e −0.1315 t . answer the following questions in complete sentences. 1. how does the exponential equation above compare to the equation for simple interest that is compounded continuously? explain the similarities. 2. what is the initial amount of cobalt-60 in the sample? 2. how much cobalt-60 is left after 8.4 years? show your work. 3. what would be the y-intercept of the graph? what does it represent? 4. after how many years will the amount of cobalt-60 left be 6.25 mg? explain what happens to the cobalt-60 after 50 years? 5. discuss some “real-world” examples and uses of cobalt-60

How many solutions does the nonlinear system of equations graphed bellow have?

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).