Problems with the Pythagorean Theorem Problems with the Pythagorean Theorem

The angle abc = 90 degrees, is the vertex of the angle b?

Angle abc = 90?Written wrong, right? Otherwise, the CD is perpendicular to D, and the D point coincides with the B point CD=CB=3, and the triangle area = 3*5 2=

Because the triangle is known to be 5, 12, 13 respectively, and because 13 2 = 12 2 + 5 2 ===> triangle is a right triangle, and 12 and 5 are right angled sides, then the triangle area = 12 * 5 2 = 30

Let the three sides of the triangle be a, b, and c, and C 2=a 2+b 2 The length of the three sides of the right triangle is expanded by the same multiple at the same time, then there is (2c) 2=4c 2=4(a 2+b 2)=4a 2+4b 2=(2a) 2+(2b) 2

So it's still a right triangle.

3.Right-angled triangle.

You don't know if you don't have a picture for the first question. , Question 2. I didn't get it. Subtriangular ?..

1.You say that CD is vertically ab to d, which is not true, and the angle b is a right angle.

2.From the length of the side, we can know that 13 is the hypotenuse, 5 and 12 are right-angled sides, and 5*12*1 2 30

3.Or a right triangle, you can give your own example, 345, doubling is 6 8 10, do you see if it is still a right triangle?

The first one, please be clear!

2.Knowing that the three sides of a triangle are 5, 12, and 13 respectively, what is the area of the sub-triangle?

The two right-angled sides are 5 and 12...The hypotenuse is 13....The area is 5*12 23What is the triangle obtained by enlarging the lengths of all three sides of a right triangle by the same multiple?

It is also a right triangle. Because such as the edge is expanded by the same multiple.

6 2 + 8 2 = 100 square root is 10...The proof is a right triangle.

The shortest path for an ant to climb a cube is actually a diagonal of a rectangle with 2a as the long side and a as the short side.

According to the Pythagorean theorem, the shortest path for an ant to climb is .

Root number (2a) 2+a 2 = root number 5a

x squared + 2 squared = (1 + x) squared.

x = 3 2 water depth is 3 2

The perpendicular lines of E and F respectively cross AB to Wheels m, nLet ab=x, bc=y, then bn=x/3, bm=2x /3, n f=2/3y me=y, 3/3 y

Then the Pythagorean theorem is used to represent be, bf. in two right-angled Lawangsan triangles, respectivelyThe square of the answer ac is 9/5

tana=bc/ac=a/b；

sina=bc/ab=a/c；

cosa=ac/ab=b/c；

cota=ac/bc=b/a；

Here we are: tana=a b=(a c) (b c)=sina cosa;

cota=b/a=(b/c)/(a/c)=cosa/sina=1/tana；

It is known from the Pythagorean theorem: a 2 + b 2 = c 2;So:

sina)^2+(cosa)^2=(a/c)^2+(b/c)^2=(a^2+b^2)/(c^2)=1；

In addition by: (c a) 2-1 = (c 2-a 2) (a 2) = (b a) 2 = (cota) 2

That is, (1 sina) 2-1=(cota) 2---csca) 2-(cota) 2=1;

The same is true: (seca) 2-(tana) 2=1;

In addition, it is also possible to introduce the double angle relationship, the method is the same as above!

Draw a right triangle and deduce it yourself according to the definition of a trigonometric function, don't be lazy, try to derive it yourself, it's not difficult.