Hello!
6.
Since the area is that of a square, you know that all side lengths are the same.
Area is base times height (A = bh), but since base and height are the same for a square, you get the formula A = a².
The length of the side of a square with an area of 144 in² is
12 in.
7.
Rational number.
8.
This is a right triangle; use the Pythagorean Theorem to find missing lengths of right triangles. Pythagorean Theorem: a² + b² = c², where c is the hypotenuse of the triangle.
Plug in your leg lengths:
a² + b² = c²
8² + x² = 21²
64 + x² = 441
x² = 377
x = 19.4
First one is c and the second im not sure on
So this is what's known as a combination. a combination is a group where the order does not matter. to solve a combination, you use this equation:
n! / (r! *(n-r)!)
n is the total number of objects being sorted (8)
r is the group you need to sort them into (4)
(i know it's 2 groups of 4 but if you solve this for 1 group, the other group is automatically made of the remaining kids)
definition of !:
a number with a ! means 1*2*3...*that number (so that number multiplied by every number smaller than it all the way to one)
so we put 8 and 4 in this equation:
8! / (4! *(8-4)!)
simplify:
8! / *(4! 4!)
multiply out:
(8*7*6*5*4*3*2*1) / (4*3*2*1 * 4*3*2*1)
and put that in your calculator
you will get 70
your answer is 70