Math Help - Need Help with complex fractions

1. Originally Posted by badandy328
Now i just need the SAT question and the triangle one.

For the triangle question. Use cosine rule to find an angle between any of the two sides, and then use the formula (1/2)absin(theta) for the area.

for instance. let the sides be a, b and c. the angle between a and b is given by:

c^2 = a^2 + b^2 - 2abcos(C), where C is the angle between a and b. Solve for C.

then, use the formula A = (1/2)absin(C) to find the area

2. Originally Posted by badandy328
Now i just need the SAT question and the triangle one.
I believe the answer to 5 is 10*10*26*26*10*10*10 = (10^5)(26^2) = 67600000 = 6.76 x 10^7

Since you have a choice of 10 digits for the first number, and also 10 digits for the second, since numbers can be repeated, and so on. Similarly, you have 26 letters to choose from for the first letter, and since letters can be repeated, you also have 26 to choose from for the second letter.

3. Originally Posted by badandy328

Now this one I thought I had down but apparently I got it wrong. I know the area of a triangle is 1/2 base*height. I used this equation and got 184000sq.ft. When i did the work afterward the work cames out to be wrong so maybe you guys know what I did wrong.

6.A triangular parcel of land has sides of lengths 400 feet, 920 feet and 1197 feet.
a) What is the area of the parcel of land?

b) If land is valued at 1500 per acre (1 acre is 43,560 feet ), what is the value of the parcel of land?
What you did wrong was that you have no height here. You are given the length of the three sides. no where does it say you should assume the triangle is a right angled triangle, so you can't use one of the sides for height. In fact, looking at the numbers, we know it's not a right angled triangle, since the square of the largest number is not equal to the sum of the squares of the other two. So, that means you do not have the height of the triangle given, neither do you have a right angled triangle. thus the tools you have available to you are the sine rule and cosine rule. you couldn't use the sine rule, since you needed to know at least one angle to do that, so the cosine rule was the only option.

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