绗?/p>
18
璁?/p>
閿愯涓夎鍑芥暟鍙婂叾搴旂敤
1
锛庨攼瑙掍笁瑙掑嚱鏁帮細濡傚浘锛屽湪
Rt
鈻?/p>
ABC
涓紝璁锯垹C锛?/p>
90
掳锛?/p>
鈭?/p>
A
銆佲垹B銆佲垹C
瀵瑰簲鐨勮竟鍒嗗埆涓?/p>
a
锛?/p>
b
锛?/p>
c
锛屽垯锛氣垹
a
鐨勬寮?/p>
sinA
锛?/p>
a
c
锛?/p>
鈭?/p>
a
鐨勪綑寮?/p>
cosA
锛?/p>
_
b
c
_
锛涒垹
a
鐨勬鍒?/p>
tanA
锛?/p>
a
b
.
2
锛庣壒娈婅鐨勪笁瑙掑嚱鏁板�?/p>
30掳锛?5掳锛?0掳鐨勪笁瑙掑嚱鏁板�硷紝濡備笅琛細
姝ｅ鸡
浣欏鸡
姝ｅ垏
30
掳
1
2
3
2
3
3
45
掳
2
2
2
2
1
60
掳
3
2
1
2
3
3.
瑙ｇ洿瑙掍笁瑙掑舰鐨勫父瑙佺被鍨嬪強瑙ｆ硶
宸茬煡鏉′欢
鍥惧舰
瑙ｆ硶
涓�鐩磋杈瑰拰涓�閿愯
(a
锛屸垹
A)
鈭燘锛?/p>
90
掳锛嶁垹A锛?/p>
c
锛?/p>
a
sinA
锛?/p>
b
锛?/p>
a
tanA