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yaroslaw [1]
3 years ago
8

Given that Triangle ABC such thata=8cm, b=7cm and c=9cmtem and c= 9cm find Cos B​

Mathematics
1 answer:
charle [14.2K]3 years ago
4 0

Answer:

We use cosine rule also called cosine law which states

c^2=a^2+b^2-2abcosC

given

a=8cm, b=7cm, c=9cm cos C?

9^2=8^+7^2-2*8*7 cos C

expand

81=64+49-112 cos C

like terms together

81-113=-112 cos C

-32=-112cos C

multiply both sides by -1

32=112cos C

divide both sides by 112

32/112=cos C

cosC=0.2857

find cos inverse of 0.2857

angle C= 73.40

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a_sh-v [17]
We know, Volume of a Sphere = 4/3 πr³
v = 4/3 * 3.14 * 18³
v = 4.186 * 5832
v = 24,416.64 cm³

Volume of a Sphere = 4/3 πr³
v = 4/3 * 3.14 * 12³
v = 4.186 * 1728
v = 7234.56 cm³

Difference = 24,416.64 - 7234.56 = 17182.08

In short, Your Answer would be: 17182.08 cm³

Hope this helps!
6 0
3 years ago
A cashier checks the price of a dining room table that is marked $369, because it is usually rings up to, $410. What percentage
lara31 [8.8K]

Answer:

10% discount

Step-by-step explanation:

If you take 369 divided by 410 it gives you 0.9 which is equal to 90% which then leads us to realized that if 369 is 90% of 410 then the discount would have to be 10%

8 0
3 years ago
Read 2 more answers
Evaluate the Expression :<br> (-2 4/5) + 2 2/3 + (-3 1/2)
denis-greek [22]

−24/5+22/3+−31/2

=38/15+−31/2

=−389/30

7 0
3 years ago
The following frequency distribution shows the yearly tuitions (in $1,000s) of a sample of private colleges.
hoa [83]

Answer:

19.714

Step-by-step explanation:

Given :

Yearly Tuition Frequency

12-16 5

17-21 4

22-26 3

27-31 2

We calculate the midpoint (x) = (lower + upper) / 2

The mean yearly tuition :

The midpoint (x) :

X ___ F ___ Fx

14 __ 5

19 __ 4

24 __ 3

29 __ 2

The mean = Σfx / Σf

Σfx / Σf = (14*5 + 19*4 + 24*3 + 29*2) / (5+4+3+2)

Mean = 276 / 14

Mean yearly tuition = 19.714

8 0
3 years ago
Find the perimeter and the area of the figure
valina [46]

Answer:

area=112

perimeter=56

3 0
2 years ago
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