1. a)CK²=CH²+HK², CH - radius
CH²=CK²-HK²=50²-30²=2500-900=1600 ft²
CH=40 ft -- radius
b) cos(KCH)= CH/CK=40/50=4/5
KCH=arccos(4/5)≈36.87°
2)C=2πr≈2*3.14*40=251.2 ft
C=2*40π=80π ft --- exact
3) A =πr²=40²π=1600π ----exact
A≈1600*3.14=5024 ft
The given expression is a perfect square trinomial.
<h3>
How to classify the given expression?</h3>
Here we have the expression:

Notice that we can rewrite it as:

Then we can see that inside the parenthesis we have a difference of squares, but it is squared, so if we define:

We will have:

Which is in fact, a perfect square trinomial.
If you want to learn more about perfect squares:
brainly.com/question/1538726
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Step-by-step explanation:
The absolute value of 10-(-6.5) is 16.5, therefore the distance between the points is 16.5 units
Let's look at each pair and change it so the first one in the pair will be what the second one will be converted to.
8,600 mg = 86,000 mg; So now, the first one is not equivalent.
2,500 g = 250,000 g; Not that one either.
3.4 kg = 3.4 kg; This one is correct. We can check by checking the last pair.
480 g = .0048 g; Nope.
So 3.4 kg, 3400 g would be the correct answer.