Search the courses, subjects, tracks, games and features, or jump straight to a page.
Learn it your way
A short class with Sarah and her students. The other ways are under More.
Sign up free to listen. Transcripts are free to read.
Today, we will start exploring how to calculate the surface area of combined solids. Who can remind us what the basic solids are?
Cuboids, cones, cylinders, spheres, and hemispheres!
Exactly! Now, when combining solids, we focus on their visible surfaces. For example, how would we find the surface area of a cylinder topped with a hemisphere?
We would calculate the curved surface areas of both the cylinder and the hemisphere!
Great! Remember this mnemonic: 'Curved Together' to help you remember to focus on the curved surfaces. Let's wrap up by noting that the combined area accounts only for the external surfaces.
Let's apply what we've learned with some examples. For a cone topped by a hemisphere, how do we start calculating the total surface area?
We want to find the curved surface area of both the cone and the hemisphere!
Correct! Let's take an example: If the heights and radii are given, how would we summarize this?
We add their curved surface areas: TSA = CSA of cone + CSA of hemisphere.
Exactly! Now, let’s practice calculating these in pairs before moving on.
Next, we shift to volumes of combined solids. Can someone explain how we approach that?
For volumes, we can just add the volumes of the individual solids, right?
That's correct! Every volume contributes fully. Let's remember the phrase, 'Total Together,' since we keep every volume intact. Can anyone give me an example?
A juice bottle with a cylindrical body and a hemispherical cap!
Yes! You would calculate both volumes and add them. Good job! Let's find some numbers to plug in next.
To summarize our lessons, we have learned how to calculate surface areas and volumes for combined solids. What are some takeaways from today?
When finding surface areas, focus on visible curves, adding them up!
And for volumes, we just add them up because there’s no overlap!
Exactly! Keep those phrases in mind—'Curved Together' and 'Total Together.' This will aid in accurate calculations for your exams!
Term
Total Surface Area
Click to flip
Term
Volume
Click to flip
Term
Curved Surface Area
Click to flip
The total area that the surface of an object occupies.
The quantity of three-dimensional space an object occupies.
The area of the curved surface of a three-dimensional solid.
The sum of all the surfaces of a three-dimensional solid.
A three-dimensional shape with six rectangular faces.
Half of a sphere.
A three-dimensional shape with a circular base and one vertex.
A three-dimensional shape with two parallel circular bases connected by a curved surface.
This section summarizes how to determine surface areas and volumes of combined solids such as cuboids, cones, cylinders, spheres, and hemispheres.
In this section, students learn to calculate surface areas and volumes of complex solids formed by combining basic solids. The section emphasizes key formulas and methods for practical applications, reinforcing previous knowledge while expanding into more complex shapes.
In this chapter, you have studied various methods for calculating surface areas and volumes of objects formed by combining different basic solids: cuboid, cone, cylinder, sphere, and hemisphere. The section emphasizes breaking down complex shapes into simpler components to find their respective surface areas and volumes accurately. Additionally, it highlights the importance of understanding the specific attributes of combined shapes, such as accounting for areas not visible or volumes that overlap.