Answer:
Part 1)
Bob's mistake was to have used the cosine instead of the sine
The measure of the missing angle is 
Part 2) The surface area of the pyramid is 
Step-by-step explanation:
Part 1)
Let
x----> the missing angle
we know that
In the right triangle o the figure
The sine of angle x is equal to divide the opposite side angle x to the hypotenuse of the right triangle


Bob's mistake was to have used the cosine instead of the sine
Part 2) we know that
The surface area of the square pyramid is equal to the area of the square base plus the area of its four lateral triangular faces
so
![SA=b^{2}+4[\frac{1}{2}(b)(h)]](https://tex.z-dn.net/?f=SA%3Db%5E%7B2%7D%2B4%5B%5Cfrac%7B1%7D%7B2%7D%28b%29%28h%29%5D)
where
b is the length side of the square
h is the height of the triangular lateral face
In this problem
-------> by an 45° angle
so



Find the value of b

Find the surface area
![SA=12^{2}+4[\frac{1}{2}(12)(6)]=288\ cm^{2}](https://tex.z-dn.net/?f=SA%3D12%5E%7B2%7D%2B4%5B%5Cfrac%7B1%7D%7B2%7D%2812%29%286%29%5D%3D288%5C%20cm%5E%7B2%7D)
Answer:
$24
Step-by-step explanation:
What you do is you just times 84 x 2/7 to get your answer.
84 x 2/7=$24 is your answer.
Answer:
480
Step-by-step explanation:
First add the numbers in the table together and put the total as a denominator in a fraction then the amount of times 2 odd numbers appeared as the numerator then put another fraction with 2,000 as the denominator and divide 2,000 by the total then multiply the numerator by that answer to get the correct answer.
Hope this helped!
could you maybe ask this again and provide an image of some sort or some more context? im not sure
Answer: 
Step-by-step explanation:
Given : The total number of cards in a deck = 52
Number of red cards = 26
There are two types of red cards : diamond and heart.
Number of diamond cards = 13
The probability that the first card is a diamond :-

Since diamond is also a red card.
Now, the total cards left = 51
The number of red cards left = 12
The probability that the second card is a red card (without repetition) is given by :-

Now, the probability of choosing a red card for the second card drawn, if the first card, drawn without replacement, was a diamond :-
