ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
Math Videos 91 videos
What is the area of the square in square units?
What is the length of the line segment?
What is the distance between the points (-5, 3) and (3, 9)?
ACT Aspire Math: Calculating the Radius of a Circle Using A Right Triangle 0 Views
Share It!
Description:
In the diagram shown, C is the center of the circle, D is the midpoint of AB, and AB = 2, while CD = 10.
Transcript
- 00:03
Okay More shmoop math for you Here we go Circle
- 00:06
time in the diagram shown sees center of the circle
- 00:09
These the mid point a b and a b is
- 00:11
too While cd that thing is ten Well what is
- 00:15
the radius of the circle Time to get rad radius
Full Transcript
- 00:22
Whatever We'll be here all night folks The radius of
- 00:24
the circle is the hypothesis of the right triangle cdb
- 00:28
or the congruent right triangle a cd we confined cb
- 00:32
using the pythagorean theorem right c b squared equals c
- 00:36
d squared plus d b squared The problem tells us
- 00:40
that two cd is ten so c d then is
- 00:44
ten over two or five Right So since d is
- 00:46
the midpoint of a b we also know that d
- 00:49
b is five right It's the same well plug these
- 00:52
values in the formula above and that gets us we'll
- 00:55
see b squared is five squared plus five sward or
- 00:57
twenty five plus twenty five or fifty Then we just
- 01:00
take square root of each side and simplify it using
- 01:03
the fact that while fifty is twenty five times too
- 01:05
Right so we got square to fifty Factor out that
- 01:07
twenty five times two We get square root of twenty
- 01:10
five which is five times for it to so that's
- 01:13
it The radius of a circle is five times Where
- 01:15
were you two units The answer is d and we
- 01:18
are done
Related Videos
Which of the following sentences provides the best description of the events in the passage?
Lucy runs to the edge of Kensington Gardens because...
Immediately before Lucy lays her hand on her father's knee, she was...
In contrast to Lucy's reaction to the lady, Mr. Rayburn's reaction is characterized by:
Mr. Rayburn is most likely reading the newspaper in order to: