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What is the angle between the hour hand and the minute hand at 2:30 on the clock?
30/12=5/2
30-[10+(5/2)]=17(1/2)
(35/2)*6=105°
At 2:30 on the clock, the degree of the angle between the hour hand and the minute hand is ()
A. 90°B. 105°C. 110°D. 120°
At 2:30, the difference between the hour hand and the minute hand is 3.5 large squares. ∵ there are 12 numbers in the clock, and the angle between each two adjacent numbers is 30 °. At 2:30, the angle between the hour hand and the minute hand is 3.5 × 30 ° = 105 °. So B
As shown in the figure: in square ABCD, the crossing point D is DP, AC is crossed at point m, AB is crossed at point n, and the extension line of CB is crossed at point P. if Mn = 1, PN = 3, the length of DM is______ ．
Let DM = x, Pb = y, and the side length of square ABCD be Z, then DN = x + 1 ∵ ad ∥ PC ∥ ADM ∥ CPM, △ PNB ∥ DNA ∥ pndn = PBAD ∥ 3x + 1 = YZ, 4x = y + ZZ = YZ + 1, 3x + 1 = 4x-1, 3x = 4 (x + 1) - x2-x, x = 2 or - 2 (rounding off), ∥ x = 2
I want to ask you, when calculating the weight, the volume I calculated is 3 cubic mm, and the density of the material is 7.85g/cm. I want to get the total amount
I calculate 3 cubic millimeter = 0.003 cubic centimeter x7.85 = 0.2355/g. Is this correct?
Yes
Taxi pricing in a city is 8 yuan within 4 kilometers (including 4 kilometers), and 1.40 yuan per kilometer after 4 kilometers
Xiao Li's house is 35 kilometers away from his grandmother's house. He takes a taxi to her house for () yuan
8+31*1.4=51.4
If the length of a rectangle is reduced by 5 cm and the width by 2 cm, then the area will be reduced by 66 square cm. At this time, the remaining part will just become a square. Find the area of the original rectangle
Suppose the side length of a square is x cm, then 2x + 5 (x + 2) = 66, 7x = 56, x = 8; then, the length of a rectangle is 8 + 5 = 13 (CM), the width is 8 + 2 = 10 (CM), and the area is 13 × 10 = 130 (square cm). Answer: the original area of a rectangle is 130 square cm
In the triangle ABC, given that angle a is equal to 45 degrees and COS angle B is equal to 4 / 5, find cos angle c?
Mathematical problems of trigonometric functions
cosC=--COS(A+B)=--(cosAcosB--sinAsinB)
So Sina = radical 2 / 2 cosa = radical 2 / 2
Because CoSb = 4 / 5, SINB = 3 / 5
So COSC
= -- root 2 / 10
The sum of a number and 13 is 24. Find the number
Let this number be X. according to the meaning of the question, we get x + 13X = 24, & nbsp; 43x = 24, & nbsp; & nbsp; X = 24 × 34, & nbsp; & nbsp; & nbsp; X = 18
Use a 12 cm long wire to form a square. The perimeter of the square is () cm? The area is () square cm?
Write the number directly!
The circumference is 12 cm
Area = 9
2000 (a times the nth power of 10) = 1.6 times the 12th power of 10 to find the value of a and n (a is greater than or equal to 1 but less than 10, n is an integer)
Trouble to know the speed of the answer is very fast!
A times 10 to the nth power = 1.6 × 10 to the 12th power △ 2000
=The 12th power of 0.0008 × 10
=8 × 10 to the power of - 4 × 10 to the power of 12
=The (- 4 + 12) power of 8 × 10
=The eighth power of 8 × 10
So a = 8, n = 8
RELATED INFORMATIONS
- 1. The clock angle is 105 degrees at 2:30 Why?
- 2. 7: 8 = 8 / 8 () = 35 divided by () = 21: () = 72 ()
- 3. Solving equation 3 ^ x + 3-3 ^ 2x + 1 = 72 The process is detailed
- 4. How to solve the equation 2x-72 = 16
- 5. Solution equation: 6 times (2x-7) = 5 times (x + 8) + 9 g
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- 7. 40% x + 24 = 2x to solve the equation
- 8. 2 / 1-x & lt; 3 / x + 9-5 3 / 2x + 1 + 6 / x + 1 > 6 / 2-x 0.5 / X-1 + 0.75 / 2x-1 ≥ 18 Solving the non negative integer solution of the inequality X / 4-1 < 2-x / 2 by 4x-4 (1-x) < 32 (1 / 6x-2) Given the inequality (2a-b) X4 / 9 about X, find the solution set of inequality (a-4b) x > 3b-2a
- 9. 7、 When is 5 (x + 2) = 5-9 (x-3) 8, 1-2 (2x-5) = 3 (3-x) 9 and X, the value of formula 4 (x-1) + 2-x and 2 (4-x) - 6 are equal
- 10. The four equations x + by = 8,2x-y = 7,3ax-5by = 9, - 3x + y = - 6 have the same solution, and the values of a and B are obtained
- 11. The clock indicates 2:15. What is the acute angle between its hour hand and minute hand? The minute hand of the clock goes every minute: 360 / 60 = 6 degrees, Hour hand per minute: 360 / 12 / 60 = 0.5 degrees, So at 2:15, the angle between the hour hand and 12:00 is 0.5 * 15 + 2 * 30 = 67.5 degrees, The angle between the minute hand and 12 o'clock is: 6 * 15 = 90 degrees, Therefore, the acute angle between the hour hand and minute hand is 90-67.5 = 22.5 degrees This is the answer. But I still don't understand! "At 2:15, the angle between the hour hand and 12:00 is 0.5 * 15 + 2 * 30 = 67.5 degrees." Why 0.5 * 15 + 2 * 30,
- 12. How many degrees did the clock turn from 2:30 p.m. to 5:15 p.m? How many degrees did the clock turn from 2:30 p.m. to 5:15 p.m?
- 13. From 8:15 to 8:25, the minute hand of the clock turns___ The angle between the hour hand and the minute hand at 2:25 is___ Degree
- 14. From 2:15 to 2:30, the angle of the minute hand of the clock is () A. 30°B. 45°C. 60°D. 90°
- 15. Given that the length of the hypotenuse of a right triangle is 24, the length of one right triangle is 16, find the length of the other right triangle
- 16. It is known that the short side of a right triangle is 15. The angle of the short side is 30 degrees?
- 17. How to find the length of the other side of a right triangle As shown in the picture Find the length of the red line A right triangle with a side length of 4251.325 and an angle of 9.46 ° is known How to make the other side grow
- 18. The ratio of diagonal length to side length of square is (), and the ratio of height to side length of isosceles right triangle is ()
- 19. It is known that the lengths of two right angles of a right triangle are 9cm and 40cm respectively, and the height on the hypotenuse is required
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