If the inscribed circle of RT triangle is tangent to the hypotenuse AB at D, and ad = 1, BD = 2, then s ABC =? AB is the hypotenuse If the inscribed circle of RT triangle and hypotenuse AB are tangent to D, and ad = 1, BD = 2, then s ABC =? AB is hypotenuse How to use area

If the inscribed circle of RT triangle is tangent to the hypotenuse AB at D, and ad = 1, BD = 2, then s ABC =? AB is the hypotenuse If the inscribed circle of RT triangle and hypotenuse AB are tangent to D, and ad = 1, BD = 2, then s ABC =? AB is hypotenuse How to use area

Let the radius of the inscribed circle be r;
It is known that ad = 1, BD = 2,
The results show that BC = 2 + R, AC = 1 + R, ab = 1 + 2 = 3,
So, s △ ABC = &# 189; (BC + AC + AB) r = R & # 178; + 3R;
From Pythagorean theorem, we can get: BC & # 178; + AC & # 178; = AB & # 178,
That is: (2 + R) &# 178; + (1 + R) &# 178; = 3 & # 178,
We can get: R & # 178; + 3R = 2,
That is: s △ ABC = 2

In a right triangle ABC, the angle c is 90 degrees, and the inscribed circle AB is tangent to d. This paper proves that AC × BC = 2ad × BD
Seeking solutions to problems

If the center of the inscribed circle is O and the radius is r, cut AC and BC at points E and F and connect OD, OE and of, then od = OE = of = R, the area of △ ABC = the area of square ecfo + the area of triangle OAB × 2, that is, AC × BC / 2 = ab × R + R × R and AC = AE + EC = AD + R, BC = BF + FC = BD + R, so AC × BC = (AD + R) × (BD + R) =

In the triangle ABC, we know BC = 2 radical 3, ab = radical 6 + radical 2, AC = 2 radical 2, find B and the area of the triangle

This problem uses cosine theorem, that is: CoSb = (AB ^ 2 BC ^ 2-ac ^ 2) / 2Ab × BC (people teach high school mathematics, forget is compulsory 4 or compulsory 5) to calculate CoSb = (4 radical 3) / 3 radical 2 radical 6
The area is half of the sine product of the two sides and the angle between them: S = 1 / 2sinb × ab × BC
SINB = under the root sign (1-cos ^ 2b), who gives the number? Why, it's hard to calculate, anyway, the method is like this

In ABC, the angle c = 90 degrees, AC = radical 2, BC = radical 6
This problem is in the mathematics book (the third part of junior high school), at the top of P90
But why can we get the root 3 of Tan a to get the angle a = 60 degrees?

Tana = root 3
Then a = 60 degree
This is the special value of trigonometric function, which should be memorized

Square, rectangle, hexagon, Pentagram whose axis of symmetry is more

Hexagon is the most
There are 4 squares, 2 rectangles, 6 hexagons and 5 pentagons

A regular hexagon has () axes of symmetry, and a regular hexagon has several axes of symmetry
A regular hexagon has () axes of symmetry, and a regular hexagon has several axes of symmetry

7, 6
A positive n-polygon (n ≥ 3) has n axes of symmetry

Five pointed star______ There is an axis of symmetry

A pentagram has five axes of symmetry, and every vertex passing through each corner has one

Regular hexagons have______ There is an axis of symmetry

As shown in the figure, the answer is: 6

Two figures are axisymmetric. Must there be only one axis of symmetry?
There may be more than one axis of symmetry in an axisymmetric figure, but if two figures are axisymmetric, is the axis unique?
The following invincible rope is wrong! You said that kind of situation, is two circles and itself symmetrical! It's not that one figure coincides with another!
Who can give a counterexample! How do I feel that if two figures are axisymmetric, there should be only one axis of symmetry!

No, look at the picture. There are two

The characteristics of two axisymmetric figures are: the distance between the corresponding point and the axis of symmetry (), the line between the corresponding point () and the axis of symmetry
Please!

The distance between the two corresponding points is the same! If you are in the second, third and fourth quadrant, you should pay attention to the positive sign instead of the negative sign when answering the questions! I'm confused about the latter question! I can't answer sorry!