Alex 發問於 科學及數學數學 · 5 年前

# S1_Mock1_15_E

In the figure, ABCD is a rectangle. E is the mid-point of BC. F is a point lying on CD such that DF = 3CF. If the area of triangleABE is 2 cm2, then the area of triangleAEF is

A.2 cm2.

B.2.5 cm2.

C.3 cm2.

D.4.5 cm2.

https://www.flickr.com/photos/130230543@N06/162925...

In the figure, the coordinates of A are (1, -1). L is a horizontal line passing through (0, 2). A is first translated to the left by 4 units to B, and then reflected about L to C. Find the coordinates of C.

A.(5, 1)

B.(-3, 1)

C.(-3, 5)

D.(5, 5)

https://www.flickr.com/photos/130230543@N06/156726...

In Figure 1, the side length of the cubic tank is 15 cm. The depth of the water in the cubic tank is 5 cm. If 3 identical metal balls are put into the tank, the depth of the water in the tank will become 7 cm (see Figure 2). Find the volume of each metal ball.

A.150 cm3

B.200 cm3

C.225 cm3

D.450 cm3

https://www.flickr.com/photos/130230543@N06/161067...

### 1 個解答

• 5 年前
最愛解答

(1)

Let BE=CE=Y

Let DF be 3X, then CF=X

Area of ABE = 4xy/2 = 2 --> xy=1

Area of ADF = (3x)(2y)/2 = 3xy = 3(1) = 3

Area of CEF = xy/2 = 1/2

Area of rectangle = (4x)(2y) = 8xy = 8

The required area = 8-3-2-1/2= 5/2

ANS: B

(2) Coordinates of B = (1-4, -1) = (-3, -1)

Coordinates of C = (-3, 2+3) = (-3, 5)

ANS: C

(3)Volume of the metal balls = 15 x 15 x (7-5) = 450

The required volume = 450/3 = 150

ANS: A

資料來源： Ben Sir!!!
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