1. What is the measure of A, to the nearest degree?
Options: 17, 33, 57, 73 dg
2. What is the measure of E,rounded to the nearest degree?
Options: 28, 36, 54, 80 dg
3. A triangle has sides lengths 5 ft, 9 ft, and 13 ft. What is the measure of the angle opposite the side that is 9 ft long? Round to the nearest degree.
Options:30, 41, 60, 87 dg
+128408 Both of these can be solved by manipulating the Law of Cosines as follows :
arccos [ (a^2 - b^2 - c^2) / [ -2(b)(c)] = A
Where "a" is the side opposite the angle we are trying to find [Angle "A"] and "b" and "c" are the other two sides
For the first, we have that
arccos [ ( 4^2 - 7^2 - 7^2) / [ -2(7)(7)] = A ≈ 33.2° = 33°
For the secomd, we have
arccos [ ( 6^2 - 7^2 - 10^2) / [ -2(7)(10)] = E ≈ 36.18° = 36°
Based on these....see if you can do the last one....if you get stuck.....let us know.....
