Answer:
3 Blue Umbrellas
Step-by-step explanation:
Given



From the question, we have:
---- i.e. 6 are not blue
---- i.e. 6 are not yellow
---- i.e. 6 are not red
Required
The number of blue umbrellas
Make B the subject in: 

Substitute:
in 

Collect like terms


Rewrite:

Substitute
in 


Divide both sides by 2

Recall that: 


Remember, these are quadrilaterals, so they must add up to 360°. Just add up the angles and then do 360 minus that number to solve for x.
Therefore:
1. 118 + 90 + 99 = 307
360 - 307 = 53
2. 110 + 96 + 78 = 284
360 - 284 = 76
3. 48 + 118 + 97 = 263
360 - 263 = 97
4. 105 + 99 + 64 = 268
360 - 268 = 92
5. 103 + 63 + 113 = 279
360 - 279 = 81
6. 95 + 80 + 88 = 263
360 - 263 = 97
Answer:
40,000
Step-by-step explanation:
Squaer pyramid
paralel plane
square base
therfor cross section is another square
Answer:
18 5/12 is the answer.
Step-by-step explanation: