The sides of a triangle are 2007, 2008, and sq. rt. 12090169. What is the measure of the angle included by the sides of length 2007 and 2008?
i dont know how to do this but i do know that the square root of 12090169 is 3477.092032.
please show work.
2007-11-03 11:52:11 · 3 answers · asked by Meow* 2 in Science & Mathematics ➔ Mathematics
You have no angles, only sides, so use the Law of Cosines.
c² = a² + b² - 2abcosC
2abcosC = a² + b² - c²
cosC = (a² + b² - c²)/(2ab)
C = arccos[(a² + b² - c²)/(2ab)]
Plug in the values.
C = arccos[(2007² + 2008² - 12,060,169) / (2*2007*2008)]
C = arccos[-4,030,056 / 8,060,112]
C = arcos(-1/2) = 120°
2007-11-03 12:05:46 · answer #1 · answered by Northstar 7 · 0⤊ 0⤋
right, i'm assuming that this triangle is scaline? I'd suggest drawing it out first, then using one of the sine rules, but I flunked my AS so I can't be much more use just in case...
2007-11-03 18:56:47 · answer #2 · answered by Anonymous · 0⤊ 1⤋
56.498398495 i use caclulator =)
2007-11-03 18:54:56 · answer #3 · answered by VASUTHEVAN s 3 · 0⤊ 1⤋