ACT Aspire Math: Calculating the Radius of a Circle Using A Right Triangle
Recommendation
Want a study guide too?
In the diagram shown, C is the center of the circle, D is the midpoint of AB, and AB = 2, while CD = 10.
ACT Aspire | Math |
ACT Aspire Math | Geometry |
Math | Geometry |
Product Type | ACT Aspire |
Test Prep | ACT Aspire ACT Aspire Math |
Transcript
Whatever We'll be here all night folks The radius of
the circle is the hypothesis of the right triangle cdb
or the congruent right triangle a cd we confined cb
using the pythagorean theorem right c b squared equals c
d squared plus d b squared The problem tells us
that two cd is ten so c d then is
ten over two or five Right So since d is
the midpoint of a b we also know that d
b is five right It's the same well plug these
values in the formula above and that gets us we'll
see b squared is five squared plus five sward or
twenty five plus twenty five or fifty Then we just
take square root of each side and simplify it using
the fact that while fifty is twenty five times too
Right so we got square to fifty Factor out that
twenty five times two We get square root of twenty
five which is five times for it to so that's
it The radius of a circle is five times Where
were you two units The answer is d and we
are done