Answer:

Step-by-step explanation:
The given number is 
We need to write this number in standard form.
Any no is given in the standard form is given by :

Where
a and b is real no and integer
It means,

Hence, this is the required solution.
Answer:
CE = 21.2
Step-by-step explanation:
CE = CD + DE = 14 + 7.2 = 21.2
Answer:
Volume = 52.5
Step-by-step explanation:
volume of a rectangular 3d shape can be calculated by length*width*height. In this case:
7*10*0.75 = 52.5
The square root of 71 is equal to 8.426149773176359...., which is between 8 and 9.
To check: square of 8 is 64, and of 9 is 81: 71 is between those two numbers, as it should be.