A developer has a triangular lot at the intersection of two streets. The streets meet at an angle of 72 degrees, and the lot has 300 feet of frontage along one street and 416 feet of frontage along the other street. Find the length of the third side of the lot.
2007-05-19 11:24:11 · 3 answers · asked by aloha_its_jackie 2 in Science & Mathematics ➔ Mathematics
x^2 = 300^2+416^2 -2(300)(416)cos72
x^2 = 90000 +173056 - 77130.64
x^2 = 185925.36
x = 431.19 feet
2007-05-19 11:42:15 · answer #1 · answered by ironduke8159 7 · 0⤊ 0⤋
Since you have information in the form of SAS (side angle side), you use Law of Cosines. Call the missing side x and note that's it's opposite the 72° angle.
x² = 300² + 416² - 2*300*416*cos72°
x = 431.2 feet
2007-05-19 19:00:28 · answer #2 · answered by Kathleen K 7 · 0⤊ 0⤋
Law of Cosine problem, just toss the numbers in.
c^2 = 300^2 + 416^2 - 2(300)(416)Cos 72. c is what you want.
2007-05-19 18:31:45 · answer #3 · answered by cattbarf 7 · 0⤊ 0⤋