Seeking a story book of Idioms It's a thick idiom story book. It's full of idiom stories. I remember the sequence of idiom stories is arranged in alphabetical order. The cover of the book seems to be turquoise green? Hard shell paper. There are more than 600 pages in total. It was given to me by my relatives in 2001 "A" begins with "An Bu bicycle", "an Qian Ma Hou"

There are 38 stories in a reading room, 6 less than twice the number of idiom stories. How many are there

22 copies

Interesting math stories

Little bear's mother is ill. In order to earn money to cure her mother's illness, little bear gets up and goes fishing in the river before dawn every day. One day, little bear just sets up a fish stand, and fox, black dog and old wolf come. Little Bear sees a customer coming, and says: "buy fish? I just caught this fish. It's fresh!" Fox

When making a call, the telephone fee changes with time. There is a difference between the telephone fee y (yuan) and the call time x (min)
When making a call, the telephone fee changes with time. There is a difference between the telephone fee y (yuan) and the call time x (min)
The relation can be approximately expressed as y = 0. 8 + 0.5x. The principal made a 36 minute call this month. How much is his call fee

Substituting x = 36 minutes into y = 0.8 + 0.5x = 18.8 yuan
So the phone bill is 18.8 yuan

Take a piece of rectangular paper for folding, the specific operation process is as follows: the first step: fold the rectangular ABCD in half, the crease is Mn, as shown in Figure 1; the second step: fold point B on the crease line Mn, the crease is AE, and the corresponding point of point B on Mn is BN, to get RT △ Abe, as shown in Figure 2; the third step: fold along the EB line, to get the crease EF, as shown in Figure 3; explore with expansion Figure 4:
(1) What triangle is △ AEF? Prove your conclusion. (2) for any rectangle, can this triangle be folded according to the above method? Please give reasons

(1) It is proved that ∵ Abe and ≌ ab ′ e are completely coincident, ≌ Abe ≌ ab ′ e, ≌ BAE = ≌ 1, EB ′ = B ′ F, and ≌ ab ′ e = 90 ° If the length of the rectangle is a and the width is B, then equilateral triangles can be formed by this method when B ≤ 32A; if 32A < B < A, then complete equilateral triangles cannot be formed by this method

It is known that the mass of one oxygen atom is 2.657 × 10-26kg, then______ The amount of oxygen is 1mol

Because oxygen is a diatomic molecule, the mass of one oxygen atom is 2.657 × 10-26kg, so the mass of oxygen molecule is 2 × 2.657 × 10-26kg = 5.314 × 10-26kg; 1mol oxygen contains 6.02 × 1023 oxygen molecules, the mass is 6.02 × 1023 × 5.314 × 10-26kg = 31.99g, so the mass of 31.99g oxygen is

The speed ratio of a and B vehicles is 5:8. The two vehicles start from a and B at the same time and meet at 24km from the midpoint. How many kilometers is the distance between a and B?

When they met, B traveled 2 * 24 = 48 kilometers more than a
When meeting, the travel ratio of Party A and Party B is also 5:8
48／（8－5）＝16
AB distance = 16 * (5 + 8) = 208 km

The waist length of an isosceles triangle is 5cm, and the area of △ ABC is 12cm 2. The length of the bottom side can be obtained by using Pythagorean theorem

Let the height be x and the length of the bottom edge be 2Y, so x ^ 2 + y ^ 2 = 25, and because 1 / 2 * x * 2Y = 12, take the following formula to the first one, and get y = 3 or y = 4
Hope it works for you

In triangle ABC, if the area of triangle is known = (square of a + square of B + square of C) / 4, then C =? A. π / 3 B. π / 4 C. π / 6 D.2 π / 3
In the triangle ABC, if the area of the triangle is known to be = (the square of a + the square of B + the square of C) / 4, then C =?
A.π/3 B.π/4 C.π/6 D.2π/3
To explain ~ ~ thank you

Cosine theorem COSC = (A & sup2; + B & sup2; - C & sup2;) / 2Ab
We obtain a & sup2; + B & sup2; - C & sup2; = 2abcosc
So s = (A & sup2; + B & sup2; - C & sup2;) / 4 = 2abcosc / 4 = (1 / 2) abcosc
The area formula s = (1 / 2) absinc
So 1 / 2abcosc = 1 / 2absinc
Sinc = COSC, C = 45 degree
B

Xiaohong's collection of foreign stamps accounts for one tenth of China's total. It is known that there are 180 more domestic stamps than foreign ones. How many are there in China?
75 + 10% X-15% x = 74 6 + (3 / 15 + 20%) x = 84
2-8 / 15 x = 17 / 10 X-15% x = 1.7

1) 180 ÷ (1-1 / 10) = 200 pieces
A: there are 200 domestic stamps
2)75+10％x-15％x=74
75-5%x=74
5%x=1
x=20
3)6+(3/15+20%)x=84
(0.2+0.2)x=84-6
0.4x=78
x=78÷0.4
x=195
4)2-8/15x=17/10
2-17/10=8/15x
8/15x=3/10
x=3/10÷8/15
x=9/16
5)x-15%x=1.7
0.85x=1.7
x=2