I think you want to prove that a rectangle is a quadrilateral. You can prove this with definitions. The definition of a quadrilateral is that it is a shape with four sides. Since a rectangle has four sides, that proves that a rectangle is a quadrilateral.
<span>x intercept when f(x) = 0
so
</span><span>x^2-81 = 0
x^2 = 81
x = + 9 and x = -9
Answer
</span><span>C -9</span>
Answer:
D
Step-by-step explanation:
Add them all then divide the amount of numbers added.
The amount of metal used to make the can = surface area of cylindrical can, which is: D. 42π in².
<h3>What is the Surface Area of a Cylinder?</h3>
A can is a cylinder.
Surface area of a cylinder = 2πrh + 2πr²
Thus:
Amount of metal used to make the can = surface area of the can
r = 6/2 = 3 in.
h = 4 in.
Therefore:
Surface area = 2×π×3×4 + 2×π×3²
Surface area = 24π + 18π
Surface area = 42π in².
Learn more about the surface area of a cylinder on:
brainly.com/question/14657844
