Yes it is right because you are measuring by either the base to height or length times width
Calculating x=3 and x=5, we get f(x)=10 and 4 respectively by plugging the numbers into the equation. Finding the difference and dividing by 2 (since there are 2 seconds between 3 and 5), we get 3, so the answer is either A or C. Since it doesn't only fall 3 feet, we need to specify that it is 3 feet per second, A is right!
The slope of y=-2x+4 is -2
All angles in a triangle add to 180 so
B = 180 - 90 - A
B = 90 - 20.8
B = 69.2
Can find b with tangent of A
tangent is opposite over adjacent.
opposite to A = 20.8 is 11.2 and adjacent is b
tan(20.8) = 11.2 / b
b = 11.2 / tan (20.8)
b = 29.5
c can be found with sine of A
sin(20.8) = 11.2 / c
c = 11.2 / sin(20.8)
c = 31.5
B = 69.2°, b = 29.5, c = 31.5
