Why can't edges and corners prove the congruence of triangles

Why can't edges and corners prove the congruence of triangles

Given two triangles, BC = B & # 39; C & # 39;, AC = A & # 39; C & # 39;, & lt; a = & lt; a & # 39;
It is SSA condition, which can't prove the congruence of two triangles,
As shown in the figure, make CD ⊥ AB, C ᦉ 39; D ᦉ 39; ⊥ a ᦉ 39; B ᦉ 39;, (foot on the bottom),
If two triangles are both acute angles or right angles, then they must be congruent. When they are acute angles, B and B are on the right side of D, D and 39;, then two triangles must be congruent,
However, if the type of two triangles is not specified, it is not sure that they are congruent,
At this point, B & # 39; is on the left side of D & # 39; (C & # 39; D & # 39; is the axis of symmetry, C & # 39; B & quot; = C & # 39; B & # 39;), one is an acute triangle, and the other is an obtuse triangle. Of course, it is not congruent

Two triangles, five elements equal, two triangles must be congruent, for example, three sides equal, two angles equal, not corresponding
The five elements are not equal

If three sides are equal, the triangle is congruent. It is impossible to find two sides which are respectively equal, and its three sides cannot correspond to each other
There is no need to think more about the two corners
Ask again

Is there a congruence of two triangles with the same height on two sides and the third side
If the title, to reason and process

The answer is no for the following reasons: in the triangle ABC and a 'B' C ', AC = AC', ab = a 'B', ad = a'd ',

If the quadratic power of X + 6xy = 26 and the quadratic power of Y - 4xy = - 19, what is the value of the quadratic power of X + 2XY + y?

x²+2xy+y²
=x²+6xy+y²-4xy
=26+(-19)
=7

The height ratio of Xiaofang, Xiaoming and Xiaoqiang is 10:9:8. Their average height is 108CM. What's the height of each of them?

The sum of three is 108 × 3 = 324 cm
So Xiaofang 324 × 10 ÷ (10 + 9 + 8) = 120 cm
Xiaoming 120 △ 10 × 9 = 108CM
Xiaoqiang 120 △ 10 × 8 = 96cm

We often use capillary phenomenon to solve problems in our life. Please give four examples

Soil water absorption
Blood test
Pen
Bricks absorb water
The towel absorbs sweat
Chalk sucks ink
Wick oil absorption

Find the maximum value of function y = x ^ 2 (1-5x) (0 ≤ x ≤ 1 / 5)

y=5/2 x x (2/5-2x)

A circular machine part, its diameter is 3.2 mm, drawn on the drawing, its diameter is 1.6 cm, find the scale of this drawing
Please let me know as soon as possible, thank you!

Scale = dimension on the drawing: actual dimension = 16mm: 3.2mm = 5:1
Not only mechanical drawing, but also architectural drawing and map industry have the same definition

Mathematics 1 yuan twice
7200(1+x)^2=8450
The first floor is wrong. That's not the answer.

(1+x)^2=8450/7200=169/108
1+x=±13/(6√3)=±13√3/18
So X1 = (- 18 + 13 √ 3) / 18, X2 = (- 18-13 √ 3) / 18
If it's not the same as the answer, it's the wrong answer, or you wrote the wrong question

Calculation of cylinder thrust
I want to make a cylinder pushing device, horizontal push a 250 kg object, but also have clamping force, stroke 60 mm, cylinder thrust is how much, air compressor with 0.5-0.7 MPa gas supply, thank you!

When the air pressure is determined, the thrust of the cylinder is directly related to its cross-sectional area. F = P * s, if the area is large, the thrust will be large