Answer:
The total surface area of this square pyramid is 
Step-by-step explanation:
we know that
The surface area of a square pyramid is equal to
![SA=b^{2} +4[\frac{1}{2}(b)(h)]](https://tex.z-dn.net/?f=SA%3Db%5E%7B2%7D%20%2B4%5B%5Cfrac%7B1%7D%7B2%7D%28b%29%28h%29%5D)
we have
----> the length side of the square base
----> the height of the triangular faces
substitute the values
![SA=9^{2} +4[\frac{1}{2}(9)(12)]=297\ mm^{2}](https://tex.z-dn.net/?f=SA%3D9%5E%7B2%7D%20%2B4%5B%5Cfrac%7B1%7D%7B2%7D%289%29%2812%29%5D%3D297%5C%20mm%5E%7B2%7D)
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
#SPJ1
here is the answer I just took a picture because I already answered this for someone eles
ANSWER: x = 130°
EXPLANATION: You must add given angles and then subtract from 180°.
Answer:
c<-3
Step-by-step explanation:
move the constant to the right-hand side and change its sing
Then canculate the difference
Then divide both sides for the inequality of 3