Mr. robinson has 20 students on his martial arts class. the ratio of boys to girls is 4: 1. how many boys and giris are in mr. robinson's class?

16 boys and 4 girls
Since there is 20 students...and the ratio is 4:1
To get to 16:4 you multiply 4 to get 16 and multiply 1 by 4 to get 4.
Now that it is 16:4 there is a total of 20 students..

Since the ratio of boys to girls is 4:1, we can represent the number of boys as 4x and the number of girls as 1x.
We know that the number of boys + girls = 20. (total number of students)
4x + 1x = 20
5x = 20
Divide by 5...
x = 4
Now that we know x = 4...
Number of boys = 4x = 4(4) = 16
Number of girls = 1x = 1(4) = 4

Okay so for every triangle has three angles that always add up to 180 degrees. and to tell the difference between whether they are secure, right or obtuse is that acute: has one angle that is less than 90 degrees. right triangle means there is at least one angle that is exactly 90 degrees. and an obtuse angle has an angle that is bigger than 180 degrees. i’ll do #13 as an example: 13. 40 and 50 so if every triangle has 180 degrees 40+50= 90 degrees then180-90= 90 degrees so the third angle is 90 degrees and because this triangle has a 90 degree angle it means it is a right triangle