Answer:
561
Step-by-step explanation:
an = dn - (a-d)
The difference is 3.
The first term is 12.
an = 3n - (12-3)
an = 3n - 9
Put n as 1, 2, 3, 4, 5 ....22.
3(1) - 9 = -6
3(2) - 9 = -3
3(3) - 9 = 0
3(4) - 9 = 3
3(5) - 9 = 6
...
3(22) - 9 = 57
Add the first 22 terms.
-6+-3+0+3+6+9+12+15+18+21+24+27+30+33+36+39+42+45+48+51+54+57
= 561
The surface area increases by a factor of 4. 2^2= 4.
The area of the long side is 3×1= 3cm^2 on the small prism.
The area of the long side is 6×2= 12cm^2 on the large prism.
12/3= 4.
Answer:
Step-by-step explanation:
If AB is tangent to the circle, then angle ABO is right angle and triangle AOB is special 
triangle. In this triangle, the leg that is opposite to the angle of 30° is half of the hypotenuse. Thus,
By the Pythagorean theorem,
Answer:
Step-by-step explanation:
Recall that ![\frac{x}{9}=\lfloor \frac{x}{9} \rfloor + 0.\overline{[x\:\mod9]}](https://tex.z-dn.net/?f=%5Cfrac%7Bx%7D%7B9%7D%3D%5Clfloor%20%5Cfrac%7Bx%7D%7B9%7D%20%5Crfloor%20%2B%200.%5Coverline%7B%5Bx%5C%3A%5Cmod9%5D%7D)
.
Therefore, 
.
