A geometry problem urgent, with additional 25

bc = root number 119 because ab*cd = ac * bc so cd = 5 root number 119 12

It is possible to use the area equality method.

ab * cd = ac * bc

Where, bc = (12 2 - 5 2) = 119cd = ac * bc ab = 5 * 119 12 = 5 119 12

Represents the root number.

It's too simple, according to the problem, you can know that Cd is perpendicular to Ab, use the Pythagorean theorem to find BC, and then use the equal area formula to find Cd, the answer is 11 times 3 times the root number of 12 times multiplied by 5

It's easy to solve with the Pythagorean theorem!

Use the triangle area definitely.

1/2 bc*ac=1/2 ab*cd

BC*AC=ab*CD is obtained

In the triangle ABC, the length of BC can be obtained by using the Pythagorean theorem.

Thus finding the cd length.

After the Pythagorean theorem, bc = 119

BC AC 2 5/2 119

ab×cd÷2＝6cd

5/2 119 6cd

cd = 119 out of 15

I do it with area. Because the grade of the right-angled edge is the same as that of the hypotenuse and the high grade, the hypotenuse can be calculated by using the Pythagorean theorem and then the cd

Solution: Passing the point e as em cd can be proved e= cde+ abe

Passing the point f as fn cd can be proved f= cdf + abf = 2 3*( cde + abe).

e:∠f =3:2

First question:

1. Connect to the AC

2. Set half of the angle DCB to be X, and half of the angle DAB to Y

3. According to the relationship between the triangle DOA and BOC (the inner angle of the triangle and 180 degrees), it is obtained: b+2x=d+2y, and x-y=(d-b) 2 equation 1 is introduced

4. According to the relationship between the triangle AEC and AOC and BOC (or DOA), (the inner angle of the triangle and 180 degrees), it is obtained: e=180-(x+y)-(180-b-2x)=(x-y)+b Eq. 2

5. Substituting Eq. 1 into Eq. 2 gives E=(B+D) 2 Eq. 3 (the answer to the first question).

The second question: 1. According to the given conditions of the question, it is obtained: d=2b, e=bx 2

2. Substitute the above into Equation 3

Derives: bx 2=3b 2 calculates, and gives x=3 answer to the second question.

This problem is relatively simple, because you only need to make an auxiliary line, repeatedly use the internal angle and theorem, and combine it with a little algebraic calculation.

However, it is more a test of patience, or hard work, so students who can't solve it should pay attention to using more scratch paper and typing more drafts, just looking at it is not enough.

I wish you all the best every day!

1) Set the vertical x and the horizontal y

4x+3y=340

x+2y=160

x=40;y=60

2)4x+3y=n

x+2y=160

290 Xie Zhou Shi n = 640-5y; 290<640-5y<306;Censen Limb y<70

When y=67; x=26;n=305。Chuntuan when y=68, x=24, n=300When y=69, x=

E is constant, it should be a fixed value, because ADE does not change, DPE does not change.

How can the three corners of this picture be equal, this look will know that it is wrong. Because it should be 2 times the angle e

Angle ACB Angle B

1: If the bottom surface of the triangular prism is a triangle with equal three sides, and its side length is 5 cm, and the side edge length is 6 cm, then the circumference of the side view of the triangular prism is {42} and the area is the root number {3 2}

2: With a planar truncated prism, the cross-sectional shape may be {3-sided} with a planar truncated prism, the cross-sectional shape may be {3-sided or 4-sided) } with a planar truncated pentagonal prism, the cross-sectional shape may be {3-sided, 4-sided or 5-sided} What pattern do you find? Regularity:

Several prisms are dictated into several sides (e.g., n prisms are 3-n sides are possible).

1: If the base surface of the triangular prism is a triangle with equal sides, and its side length is 5cm, and the side edge length is 6cm, then the circumference of the side view of the triangular prism is {42} and the area is {75 root number 3 2}

2: With a plane truncated prism, the cross-sectional shape may be {trilateral} with a planar truncated prism, the cross-sectional shape may be {three or quadrilateral} with a planar truncated pentagonal prism, the cross-sectional shape may be {three or four or five deformations} What law did you find?

Summarize it yourself)

1) Circumference 6*2+2*3*5=42

Area root number 3 4 * 25 * 6 = 75 root number 3 2

3. Edges. 3, 4 sides.

3. Edges.

The title gives a regular triangular prism, the perimeter and the law are like this, but the side view is not a rectangle?

Area = length * width = 15 * 6 = 90 (cm)?

Because e=60, b+ d=60, so 2+ 3=30, so bfd=30

Solution: Extend BF to cross CD with G

abe=60

The same goes for 3= 4=30

ab‖cd∠1=∠bgd=30

bfd=∠4+∠bgd

60 When you encounter this kind of problem in parallel lines in the future, you can extend it or make parallel lines, and there are many ways.

Solution: The parallel line that crosses point f to make ab intersects with be at point g

abe＝60º

Again 1 2

Same as 3 30

ab‖fg∠afg＝∠1＝30º

The same goes for BFG 3 30

bfd＝∠afg＋bfg

Actually, there are other solutions to this problem. But the method of making auxiliary lines is simpler and easier to understand.