Answer:
A. 17
Step-by-step explanation:
using the cosine rule (also see attached for reference):
AB² = BC² + AC² - 2·AC·BC cos C
2·AC·BC cos C = BC² + AC² - AB²
Given that AC = 18, AB = 12 and BC = 18, substituting these into the formula
2(18)(28) cos C = 28² + 18² - 12²
1008 cos C = 964
cos C = 964/1008
cos C = 0.9563
C = cos⁻¹ 0.9563
C = 16.99 ( = 17° rounded to nearest degree)
Answer:
Step-by-step explanation:
First both the rational numbers should have same denominators. So, find least common denominator
Least common denominator is 10

Now multiply the numerator and denominators of the both the numbers by 10.

Answer:
Option c, A square matrix
Step-by-step explanation:
Given system of linear equations are



Now to find the type of matrix can be formed by using this system
of equations
From the given system of linear equations we can form a matrix
Let A be a matrix
A matrix can be written by
A=co-efficient of x of 1st linear equation co-efficient of y of 1st linear equation constant of 1st terms linear equation
co-efficient of x of 2st linear equation co-efficient of y of 2st linear equation constant of 2st terms linear equation
co-efficient of x of 3st linear equation co-efficient of y of 3st linear equation constant of 3st terms linear equation 
which is a
matrix.
Therefore A can be written as
A= ![\left[\begin{array}{lll}3&-2&-2\\7&3&26\\-1&-11&46\end{array}\right] 3\times 3](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Blll%7D3%26-2%26-2%5C%5C7%263%2626%5C%5C-1%26-11%2646%5Cend%7Barray%7D%5Cright%5D%203%5Ctimes%203)
Matrix "A" is a
matrix so that it has 3 rows and 3 columns
A square matrix has equal rows and equal columns
Since matrix "A" has equal rows and columns Therefore it must be a square matrix
Therefore the given system of linear equation forms a square matrix
Answer: the answer is 26 x 37 = 962 and i will post how to solv it
Step-by-step explanation: