Answer:
x = 30 degrees
Step-by-step explanation:
These triangles are perfectly symetrical. This is shown by the length of sides given in the problem. Since the triangle is symetrical, E is equal to B just as D is equal to C. Since B is 30 degrees, we can tell that E is also 30 degree.
In this problem you will need to use the Pythagorean theorem (c^2=a^2+b^2).
The a and b represents the two edges, while c is the diagonal side and it is called the hypotenuse. Since you already know what the hypotenuse is and what one of the sides already are you just have to use the problem: c^2-a^2=b^2. Then if you plug the data you already have into the problem you will get 10^2-6^2=b^2. That then equals 100-36=b^2. Then you subtract and get b^2=64. Then you square root both sides and you get the answer b=8.
I'd use synthetic div. here, with 2 as my divisor:
________________
2 / 1 -11 18
2 -18
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1 -9 0
Note that the coefficients of the missing factor are given here and are 1 and -9. Thus, (x-9) is the missing factor.