suppose a:b:c = 3:7:9
find the large angle of 三角形ABC
trigo. problem
2011-03-16 5:34 am
回答 (2)
2011-03-16 5:44 am
✔ 最佳答案
Let a = 3k, b = 7k and c = 9kBy ∠ sum of Δ,
3k + 7k + 9k = 180
19k = 180
k = 180/19
The largest angle of ΔABC = 9(180/19) = 1620/19 (~85.3 deg, corr. to 3 sig. fig.)
參考: Knowledge is power.
2011-03-16 7:36 am
suppose a：b：c = 3：7：9
find the large angle of 三角形ABC
Sol
Cosw
=(3^2+7^2-9^2)/(2*3*7)
=(9+49-81)/42
=-23/42
w=123.2度
find the large angle of 三角形ABC
Sol
Cosw
=(3^2+7^2-9^2)/(2*3*7)
=(9+49-81)/42
=-23/42
w=123.2度
收錄日期: 2021-04-25 17:07:29
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110315000051KK01219