Question

daybyday

國三數學相似形
求解

10
12
X= 240
(A)5與6 (B)6與7 (C)7與8(D)8與9
31. ( )如圖,在四邊形ABCD中,已知AB || EF || DG,且
BF:FG:GC=2:1:2,2AE=3BF,則AD:
BC=?(A)2:3 (B)4:5 (C)7:9 (D)9:10
A
EOD
X-10
BEFAGAC
32. (C)側面為梯形的水桶,下面寬8公分,上面開口寬為
20 公分,桶高12公分,今裝滿9公分的水,求液
面AB的長為多少公分?(A)8(B)12(C)17(D)20
20
3...X..
-4:x
A B
9

33. ( )如圖,AB CD、GH分別垂直EF,已知AB=12,
CD=8,且BH="DH,則GH=?
35.
A
G
E
B3%ED
(A)6 (B)4 (C)4.5 (D)4.8
34. ( )如圖,已知 DF = CE=12公分,AC=20 公分,BF
=24公分,則四邊形 DFCE 的周长是多少公分?
A
D
E
Y2
1120°
60%
24 F
B
C
(A)48 (B)56 (C)64 (D)72
家寶想知道日本 別府主其知名地酒泉的
40. (

?
2
27. ( )如圖,△ABC中,若∠ABC=90°,BH | AC
1 › BD
平分∠ABC。已知AB=3,BC=4,則DH=?
16
3
9= 5X, 1-5
=
HD Y
3
3
C
16
16= 4 x 5, y = 5
B
12
17
21
27
(A) (B) (C) ()²
35
35
35
35

Answer 1

✨ 最佳解答 ✨

Mer

31.
AE : BF = 3:2
AE : ED = BF : FG = 2:1
所以ED = 3/2，AD = 9/2
AD : BC = (9/2):5 = 9:10

Mer

33.
DH : DB = GH : AB
2:5 = GH : 12，GH = 24/5 = 4.8

Mer

34.
DFCE是平行四邊形
所以DE = FC = x
8:20 = x : (24+x)

Mer

27.
AH = 9/5
BA : BC = AD : DC = 3:4
AD = (3/7)AC = 15/7
DH = (15/7)-(9/5) = 12/35

daybyday

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