Tan80=5.67
2tan70+tan10=5.67
So tan80=2tan70+tan10
The samples he chose may not be a representative sample because the number of students per foreign language class may not be the same. One class may have a very large number of students while another may have only a few. Taking equal number of students per class is not a representative sample.<span />
1/5 of 20 is 4.
2/5 of 20 is 8.
Therefore, Ron used 8 apples to make his pies.
The picture in the attached figure
we know that
area of the <span>the shaded region=area of rectangle -area of a kite
area of rectangle=(3x+x)*(x+x)----> 4x*2x---> 8x</span>²
area of a kite=(1/2)*[d1*d2]
where d1 and d2 are the diagonals
d1=4x
d2=2x
so
area of a kite=(1/2)*[4x*2x]----> 4x²
area of the the shaded region=8x²-4x²-----> 4x²
the answer is 4x²