如圖
https://www.facebook.com/photo.php?fbid=1481118528785723&set=a.1481105148787061.1073741846.100006627693181&type=3&theater
等腰三角形ABC,角B的角平分線與角C的角平分線交於P點,若角A=68度
則角P=?度
正解為34度
如圖
https://www.facebook.com/photo.php?fbid=1481118385452404&set=a.1481105148787061.1073741846.100006627693181&type=3&theater
AC=AB,.角BAC=90度,BC=CE分別垂直X軸
B(-12,8)
C(11,15)
求A點座標?
正解為(3,0)
如圖
https://www.facebook.com/photo.php?fbid=1481118502119059&set=a.1481105148787061.1073741846.100006627693181&type=3&theater
三角形ABC,
AC=AB,AE=DE=BD=BC,求角A?
正解為180/ 7
https://www.facebook.com/photo.php?fbid=1481118402119069&set=a.1481105148787061.1073741846.100006627693181&type=3&theater
如圖
三角形ABC角A=70,角B=60由P點出發,經A.B到C問共轉了幾度??
正解為190度
這是國二數學!謝謝高手~
超火急!!求角度!今天5點前需要有過程!!數學高手幫我
2014-04-28 11:43 pm
回答 (12)
2014-06-05 2:53 pm
2014-05-30 4:40 pm
2014-05-29 5:18 pm
2014-05-27 1:31 pm
2014-05-24 2:27 pm
2014-05-08 2:27 pm
2014-05-04 3:50 pm
2014-05-02 1:49 pm
2014-05-01 3:39 pm
2014-04-29 10:49 am
2014-04-29 3:47 am
1.AC相交BP於DA=68, B/2=x, C外角/2=y, PDC=AZD=z外角=兩內角合和: 2y=68+2x => y=x+34外角=兩內角合和: z=x+(180-2y)=180+x-2yP=180-y-z=180-(x+34)-(180+x-2y)=-2x-34+2y=-2x-34+2(x+34)=-34+68=34
2014-04-28 19:50:32 補充：
2.A=(x,0), B=(-12,8), C=(11,15)
AB=AC => (x-11)^2+225=(x+12)^2+64
-22x+121+225=24x+144+64
46x=138 => x=3
=> A=(3,0)......ans
2014-04-28 20:25:31 補充：
3.Let A=x=? => C=B=90-x/2
DBC=y
=180-2*(90-x/2).....BD=BC
=180-180+x
=x
DBE=90-x/2-y=90-3x/2
DE=DB => DEB=DBE=90-3x/2
AE=ED => A=ADE=x
外角=兩內角合和: 90-3x/2=x+x
90=2x+3x/2=7x/2
x=180/7......ans
2014-04-28 20:47:57 補充：
3.+=反時鐘, -=順時鐘
公式: angle(PQ,QR)=兩箭頭的夾角
angle(PA,AB)=-70
angle(AB,BC)=120
angle(BC,CA)=130
Sum=-70+120+130=180(deg)
2014-04-29 04:12:52 補充：
如果不分正轉或反轉.則:
angle(P,C)=70+120=190(deg)
2014-04-28 19:50:32 補充：
2.A=(x,0), B=(-12,8), C=(11,15)
AB=AC => (x-11)^2+225=(x+12)^2+64
-22x+121+225=24x+144+64
46x=138 => x=3
=> A=(3,0)......ans
2014-04-28 20:25:31 補充：
3.Let A=x=? => C=B=90-x/2
DBC=y
=180-2*(90-x/2).....BD=BC
=180-180+x
=x
DBE=90-x/2-y=90-3x/2
DE=DB => DEB=DBE=90-3x/2
AE=ED => A=ADE=x
外角=兩內角合和: 90-3x/2=x+x
90=2x+3x/2=7x/2
x=180/7......ans
2014-04-28 20:47:57 補充：
3.+=反時鐘, -=順時鐘
公式: angle(PQ,QR)=兩箭頭的夾角
angle(PA,AB)=-70
angle(AB,BC)=120
angle(BC,CA)=130
Sum=-70+120+130=180(deg)
2014-04-29 04:12:52 補充：
如果不分正轉或反轉.則:
angle(P,C)=70+120=190(deg)
收錄日期: 2021-04-30 18:43:30
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20140428000010KK04353