1/23/17 class progress

30 min of practice:

https://www.khanacademy.org/math/geometry-home/geometry-volume-surface-area/volume-tutorial/e/solid_geometry

The goal of this exercise was to find volumes and surface areas of boxes, cylinders, and triangular prisms.

Notes: 

The volume of a cylinder is the area of the base × height.

SURFACE AREA: pi × r^2= pi × 2^2=4 × pi

VOLUME: The areas of the top and the base are simply the area of a circle:pi × r^2 = ? , then multiply by height 

This exercise was more difficult than expected. Finally after the 30 minutes, I was able to successfully complete the exercise and earn 475 energy points.

EXAMPLES:

FINDING SURFACE AREA-

Image result for cylinder radius=4    height=5

pi × r^2= pi × 4^2= 16 pi

circumference: 2(pi)(r)=2(pi) × 4=8(pi)

Surface Area: wh= 8(pi) × 5=40(pi)

TOTAL: 16 (pi) +16(pi)=40(pi)=72(pi)

FINDING VOLUME-

AREA=(pi)r^2=#(pi) × h=volume

WORK TIME:

So for the rest of class I found the surface area and volumes for both the cylinder and cone I created. I was having trouble at first with comprehending the formula and how to do it but then I looked at what google had to offer.

Cone:

Surface area-

A= πr(r+(square root)h^2+r^2)

Volume-

V=πr^2h/3

 

Cylinder:

Surface area-

A=2πrh+2πr^2

 

Volume-

V=πr^2h
In conclusion, in the end, when I finally got the hang of it, it was pretty easy. But I still need to practice if I am going to continue making 3d shapes.
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s