There are 45 girls in Jonathan's class.
Supplementary, complementary, neither

The probability of getting 0 heads in 4 tosses (or equivalently, 4 tails) is

.
So the desired probability is
When added, these two angles are supplementary, meaning that their sum is 180. This means that we can do the following to find x, and eventually DBC:
3x+67+4x+50=180
Simplifies to:
7x+117=180
Then by the Subtraction Prop. of Equality:
7x=63
Then divide by 7 on both sides to get that x=9.
We then substitute 9 into angle DBC.
4(9)+50
=36+50
DBC=86
:)
The perimeter of a rectangle can be found by dividing the area by one side.
30/6=5
Then, add the sides up and you get the perimeter.
5+5+6+6=22
The answer is 22 inches.