Answer: 21
Step-by-step explanation:
9x7=63
63/3=21
Answer: 20%
Step-by-step explanation: Basically you find the difference which is twelve, and put it over the original amount which is 60. You get 1/5 which in percent form is 20%
Is this a right triangle or triangle is solving for?
If the gym is a square with 17 meters sides, its area is given (as any other square) by the square of the side:

So, the area of the classroom is

We can deduce the side of the classroom only assuming that it is a square as well: if this is the case, the side of a square with given area is the square root of the area, so we have

7n^2 + 5 = 453
Subtract 5 from both sides:
7n^2 = 448
Divide both sides by 7:
N^2 = 64
Take the square root of both sides:
N = 8