Answer:
36cm^2
Step-by-step explanation:
4cm×9cm=36cm^2
Answer:
The degrees of freedom are given by:

The significance level is
and then the critical value can be founded in th chi square table we need a quantile that accumulates 0.05 of the area in the right tail of the distribution and for this case is:

And if the chi square statistic is higher than the critical value we can reject the null hypothesis in favor of the alternative.
Step-by-step explanation:
We have the followign system of hypothesis:
Null hypothesis: 
Alternative hypothesis: 
The degrees of freedom are given by:

The significance level is
and then the critical value can be founded in th chi square table we need a quantile that accumulates 0.05 of the area in the right tail of the distribution and for this case is:

And if the chi square statistic is higher than the critical value we can reject the null hypothesis in favor of the alternative.
<span>Let us use the variable x for length. So width will be 1/2x + 3.
Perimeter = x+x+ 1/2x + 3 +1/2x + 3 = 3x + 6 = 66
Therefore 3x = 66-6 = 60
So x = 60/3 = 20
The length is 20 cm.
Therefore the width = 1/2 of 20 + 3 = 10 + 3 = 13 cm
Check: 20+20+13+13 = 66</span>
One example is if you wanted to measure the height of a tall building. You'll need to measure the distance from where you're standing to the base of the building. You'll also need the angle of elevation. To get the angle of elevation, start by looking completely horizontal, then tilt upward until your eyeline reaches the top of the building. Once you have those two things (the side and angle) you can use the tangent ratio to find the height. This is because
tan(angle) = opposite/adjacent
where in this case
angle = angle of elevation
opposite = height of building
adjacent = distance from your position to the base of the building
It takes a bit of algebra, but the opposite side can be solved for. You'll most likely need a calculator to compute the tangent ratio.