For the first question, we had to find the outside surface area of the chimney, which looked like this:
In order to find the surface area, first, we had to take the cylinders apart, as shown:
So, next, we had to find the radius:
r = d/2
r = 30/2
r = 15
r = d/2
r = 50/2
r = 25
After that, then we could complete the formula (remember, it said to give your answer to the nearest hundredth of a square metre):
The answer would now be 1.92m^2.
The second question we had to figure out, was finding the total area of the surfaces needed to be painted inside of a swimming pool, which looked like this:
Then, we had to take the shapes apart so that we could easily find the surface area:
Now, time to solve for the surface area (once again, to the nearest square metre):
- Questions #13, 15, and 16 in the textbook (pg. 34-35)
- Vocabulary Link
- Chapter One Reviews (both from the textbook and the homework book)
Try to do as many questions as you can! It's great practice for your Surface Area test on Wednesday! If you don't know what the test will be on, make sure you study:
- square and rectangular based prisms
- triangular based prism
- composite shapes (made up of 2 or more shapes)
If you don't understand any of the questions that you have attempted, be sure to ask Mr. Backe for help.
Also, if there is anything that I may have missed out in writing this post, please tell me and I'll fix it right away!
Now, the person who will do the next blog post is...
Yes, I chose you.
Don't forget to do your homework and study for Wednesday's test!