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)
Answer:
$3.45
Step-by-step explanation:
The tip is 15% of his breakfast, that means 15% of 23
That is 15%* 23= 15*23/100= 3.45 $
The tip is $3.45
Have a good day.