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

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

Let the length of the hypotenuse be a and the height of the hypotenuse be H
According to the Pythagorean theorem, the length of the hypotenuse is: a = under the root sign (9 & # 178; + 40 & # 178;) = 41
Then, from "equal area", we get the equation: 0.5 x 9 x 40 = 0.5 x 41 x H [the formulas on both sides of the equal sign represent the area of the triangle]
Thus, H = 360 / 41

500 minus 7600 divided by 25 (simple algorithm)

500-7600÷25
=500-7600×4÷（25×4）
=500-30400÷100
=500-304
=196

If you read a story book, Mingming read 82 pages in three days, and Congcong read 26 pages every day in the first two days. How many pages of story books must Cong Cong read in the third day to surpass Mingming?

Consistent with Mingming, see: 82 - 2x26 = 30 (page)
Because to surpass Mingming, at least look at: 30 + 1 = 31 (page)
Hope to help you~

What are the ancients' views on 20, 30, 40, 60, 70 and 100 years old?

In ancient times, age was called Xiaoji swaddling: under one year old. Childhood: two to three years old. Shibi, Yinian: girl seven years old. Shibi, Yinian: boy eight years old. Note: according to the physiological condition, boy eight years old, girl seven years old change teeth, take off deciduous teeth, grow permanent teeth, then called "Bi", "Yinian" or "Yinian"

Four times of a number is 120. What's eight times of this number? The formula is

120 ÷4×8=240

The whole family went to the park to play, only Xiaogang did his homework at home
Write the reason and the sentence to be corrected

Only Xiaogang did his homework at home, and the rest of the family went to the park to play
Reason: inconsistency

1990, 1996, 1998, 2000, 2008, 2010 which are leap years

199620002008 is a leap year

14 times 5 times what equals 20?

Two out of seven 2 / 7
14*5=70
70*2/7=20
Thank you

Xiao gang went to his classmate Xiao Ming's house to play. Xiao Ming's house lived on the tenth floor. It happened that the elevator was being repaired, so xiao gang had to go up
It takes 48 seconds to walk from the first floor to the fourth floor. How long does it take for him to walk to the 10th floor at the same speed?

Xiao Gang is not miserable. Our dormitory is on the 12th floor. We have to climb even if there is a power failure. Unfortunately, we will be trapped in the elevator
Now solve the problem:
Layer 1 to layer 4 is 4-1 = 3, the time of three steps is 48 seconds, and the time of each step is 48 △ 3 = 16 (seconds)
The 10th floor is from the 1st floor to the 10th floor, 10-1 = 9 nine steps, the total time is 16 × 9 = 144 (seconds) = 2 minutes 24 seconds
A: it takes him two minutes and 24 seconds to get to the 10th floor at the same speed

English translation
Don't let in
Get along well with

keep sb off\ away.get along (well) with sb