Answer: Number 1 is c=89 ft
Number 2 is b=3 cm
Step-by-step explanation: a²+b²=c²
For number 1, 39 ft is a and 80 ft is b so
39²+80²=c² so 39² is 39x39=1521 and 80² is 80x80=6400 so 6400+1521=7921
7921=c² and the square root of 7921 is 89 so c=89 ft
For number 2, a=1.6 cm and c=3.4 cm so 3.4²-1.6²=b²
3.4² so 3.4x3.4 which is 11.56
1.6² so 1.6x1.6 which is 2.56
11.56-2.56=c² and 11.56-2.56=9
Square root of 9 is 3 so b=3
So number 2 answer is b=3 cm
I hope this helps
For Commutative Property of Addition
Let us take a decimal number
and a fraction 
Now, according to the Commutative property of Addition:
For any two numbers
and
:

So, for
and 
Let us add


Also,


Therefore, 
Hence, Commutative Property of Addition is satisfied.
For Associated Property of Addition
Let us take two same decimal numbers
,
and a fraction 
Now, according to the Associated property of Addition:
For any three numbers
,
and 

So, for
,
and 
The Left hand side:







The Right hand side:






Thus,

Therefore, 
Hence, Associative Property of Addition is satisfied.
Number 1 is 6 number two is -8 and number three is -10
Answer:
<h2>
<em><u>The answer is: 18</u></em></h2>
<em><u>Hope this helps you! </u></em><em><u>.</u></em>