Answer:
Part 1) The perimeter is 
Part 2) The diagonal is 
Step-by-step explanation:
<u><em>The question in English is</em></u>
You have a rectangle whose base is twice the height and its area is 12
square centimeters. Calculate the perimeter of the rectangle and its diagonal
step 1
Find the dimensions of rectangle
we know that
The area of rectangle is equal to


so
----> equation A
The base is twice the height
so
----> equation B
substitute equation B in equation A

Find the value of b

step 2
Find the perimeter of rectangle
The perimeter is given by

substitute

step 3
Find the diagonal of rectangle
Applying the Pythagorean Theorem

substitute



199, it rounds to 200 because it's closer to 200 than 100. It is also closer to 200 than to 190. And finally, 1 + 9 + 9 = 19
21^2/0.219 = 2013.69863
2 significant figures are the 20, so the answer is 2000
I think the answer might be x=24
Answer:
So the final answer is

Step-by-step explanation:
Radicals:
In mathematics, a radical expression is defined as any expression containing a radical (√) symbol. Many people mistakenly call this a 'square root' symbol, and many times it is used to determine the square root of a number. However, it can also be used to describe a cube root, a fourth root, or higher.
The given expression is

Now take common radical out so we will get

Now add the Parenthesis part.

So the final answer is
