ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
ACT Math Videos 164 videos
ACT Math: Trigonometry Drill 1, Problem 1. What is the length of y?
ACT Math: Coordinate Geometry Drill 1, Problem 2. Solve the inequality and determine which solution is shown on the number line.
ACT Math 2.5 Plane Geometry 464 Views
Share It!
Description:
ACT Math Plane Geometry Drill 2, Problem 5. What is the surface area of a rigid circular cone with diameter = 10 and height = 12?
Transcript
- 00:02
Here's your shmoop du jour.
- 00:04
What is the surface area of a rigid circular cone with diameter = 10 and height = 12?
- 00:12
And here are the potential answers...
- 00:15
Okay, it's yet another formula trivia contest.
- 00:19
So the formula is....
Full Transcript
- 00:21
surface area equals pi times r times the square root of the quantity radius squared plus height squared.
- 00:27
Well, they give us the height. Now we need the diameter to tell us what the radius is;
- 00:32
...and in a circle, here is the diameter -- the radius is just half of it. So if diameter is 10
- 00:38
half is 5.
- 00:41
Now just plug in the numbers.
- 00:43
It's pi times 5 times the square root quantity of 5 squared plus 12 squared which simplifies to
- 00:49
5 pi times the square root quantity 25 plus 144 or 169 -- and ooh magic number --
- 00:58
169 should trigger a bell in your head.
- 01:02
It is 13 squared.
- 01:04
So we have 5 times pi times 13 -- 5 times 13 is 65 so the answer is 65 pi.
- 01:11
Answer D.
Related Videos
ACT Math: Plane Geometry Drill 3, Problem 1. What is the area of the trapezoid shape in the video?
Los cubos de hielo no son ruidosos generalmente...pero tienen un volumen de tipo diferente. Este video te enseñará cómo encontrar el volumen de...
Volume is crucial to our lives. It determines the amount of food we eat, the amount of fluid we drink, and hydraulics, just to to name a few. One o...
ACT Math: Coordinate Geometry Drill 1, Problem 1. Which inequality is expressed by the number line?
ACT Math: Intermediate Algebra: Drill 3, Problem 1. Find the fifth number in the series.