Cone geometry at Elementary math level, only requires that your child can calculate the volume and the surface area of a cone. In general establishing the formula for these is not required. Your child simply needs to know the formula and how to use it to calculate area and volume.
They should also have a firm understanding of the different types of triangles and their properties.
Sometimes being told "because it is" is just not satisfying for a student. If your child is making statements like .. "I know the formula for the volume of a cone, but I want to know WHY?" ... then congratulations, these are the signs of a budding mathematician!
And because these children do exist, I have created the explanations for you here.
Bellow are the formula for the cones surface area and volume. If you need further explanations as to how these came about hang around!
Click on each of the images, to be taken to a more detailed look at each formula.
In this formula: t = slant height of the cone.
The Lateral Surface area is the surface area without the base (like a party hat!
If your student is happy accepting this formula, then that is all you need to expect from them. If however they need more explanation and proof that this formula wasn't just plucked out of thin air - click on the image for a full explanation.
In this formula:
B = Area of Cones Base, which of course the the area of a circle.
Again, if your child is happy using this formula without knowing where it comes from, then let them stop here. They DO NOT need to know this information in elementary school.
However, if your student is questioning the formulas origins - then, click on the image to be taken to an explanation page with wonderful diagrams at each step of the process.
As always, don't forget to use our free printable geometry worksheets to offer math practice to your child.
I am sure you will find all the information and worksheets you need here, however if there is anything you cannot find please don't hesitate to contact me or simply visit the K6Math Café and join the conversation!
I love to hear from my readers, and with a little feedback and a few suggestions I can make this a great resource for parents, teachers and tutors alike.
Be sure to explore everything on this site starting at the home page.