p . 34
Find the values of all the unknown in the following figures.
2. http://www.flickr.com/photos/29635386@N06/3751741656/
X = ---------------
3. http://www.flickr.com/photos/29635386@N06/3750951089/
A =---------------
4. http://www.flickr.com/photos/29635386@N06/3751741638/
B =---------------
5. http://www.flickr.com/photos/29635386@N06/3751741868/
X =------------- , Y =---------------
6. http://www.flickr.com/photos/29635386@N06/3750951155/
X = ------------ , Y =---------------- , Z =----------------
7. http://www.flickr.com/photos/29635386@N06/3751741686/
X =------------- , Y = --------------
8. http://www.flickr.com/photos/29635386@N06/3751741882/
This is a regular pentagon.
X =-------------- , Y =---------------
maths! maths! maths!
2009-08-06 9:33 pm
回答 (2)
2009-08-06 11:12 pm
✔ 最佳答案
2. x = 110oSum of exterior angles:
x + 130o+ 120o = 360o
x = 110o
3. a = 95o
Sum of interior angles:
a + 80o + 60o + (180o - 55o) = 360o
a = 95o
4. b = 45o
Sum of exterior angles:
b + 2b + 70o + 75o + 80o = 360o
3b = 135o
b = 45o
5. x = 65o, y = 65o
Int. angles of //:
50 + x + x = 180o
2x = 130o
x = 65o
alt. angles of //:
y = x
y = 65o
6. x = 50o, y = 40o, z = 90o
Alt. angles of //:
x = 50o, y = 40o
Sum of int. angles of the upper Δ:
x + y + z = 180o
50o + 40o + z = 180o
z = 90o
7. x = 130o, y = 40o
Corr. angles of //:
180o - x = 50o
x = 130o
Ext. angle of Δ:
x = y + 90o
y + 90o = 140
y = 40o
8. x = 60o
ΔBDF is an equilateral triangle.
x = 60o
(There is no y in the diagram.)
2009-08-06 11:13 pm
2. X = 110
3. a =95
4. b=45
5. x=65 y=65
6. x=50 y=40 z=90
7. x=130 y=40
8. x=60 有y咩= =?
3. a =95
4. b=45
5. x=65 y=65
6. x=50 y=40 z=90
7. x=130 y=40
8. x=60 有y咩= =?
參考: Myself
收錄日期: 2021-04-30 12:56:19
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