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.
![A = a^{2}](https://tex.z-dn.net/?f=A%20%3D%20a%5E%7B2%7D%20)
![144 = a^{2}](https://tex.z-dn.net/?f=144%20%3D%20a%5E%7B2%7D%20)
![\sqrt{144} = a](https://tex.z-dn.net/?f=%20%5Csqrt%7B144%7D%20%3D%20a)
![12 = a](https://tex.z-dn.net/?f=12%20%3D%20a)
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
Answer - to solve for the equivalent equation of r you would need to use the formula r=c/pi2.
Answer:
area is 90 and perimeter is 46
Step-by-step explanation:
the area for a rectangle is l * w, so 18*5 is 90, and the perimeter is 2l+2w, which is 46.