the operation:

Gives a square number.
<h3>
How to get a perfect square?</h3>
A perfect square is the product of a number and itself.
As you can see in the example, 16 is a square number. Then let's try to get 16.
To get 16 we can use the difference:
20 - 4
So the first therm needs to be equal to 20, and the second equal to 4.
To write 20 in scientific notation we have:

To write 4 in in scientific notation:

Then the operation:

Gives a square number.
If you want to learn more about square numbers:
brainly.com/question/21694652
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Answer:
7x+21
Step-by-step explanation:
The <span>isosceles triangle has two congruent sides
Their lengths are (</span> x + 3.8 ) and <span>16
Equate them :
x+3.8=16
Solve for x:
3=16-3.8=12.2
</span>
Answer:
90degrees
Step-by-step explanation: