Answer:


Step-by-step explanation:
Given

--- lower diameter
--- upper diameter
Solving (a): The curved surface area
This is calculated as:

Where
--- lower radius
--- upper radius
And
---- l represents the slant height of the frustrum





So, we have:




Solving (b): The volume
This is calculated as:

This gives:





Answer:
A good rule is to change 10 to 15 percent of the water each week. If your tank is heavily stocked, bump that up to 20 percent each week. A lightly stocked aquarium can maybe get by for two to four weeks, but this should be the maximum length of time between water changes.
Step-by-step explanation:
This is the correct answer you want
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Answer:
Angle C = 45 degrees.
Angle D = 30 degrees.
Step-by-step explanation:
Angle C = 45 + 90 = 135 180 - 135 = 45.
Angle D = 180 - 45 = 135 (angle F) 15 + 135 = 150 180 - 150 = 30
It’s the first one because it has 7 rows and 7 columns which show that it is 7 times 7 or 7^2.