blushlion637Lv1
29 Dec 2021
Problem 68
Page 575
Section 8.2: Series
Chapter 8: Infinite Sequences and Series
Textbook ExpertVerified Tutor
29 Dec 2021
Given information
In the given figure there are infinitely many circles approaching the vertices of an equilateral triangle, each circle touching other circles and sides of the triangle. The length of each sides of the triangle is
Step-by-step explanation
Step 1.
We are given that the triangle is equilateral, basic geometry tells us that the inscribed circle of such a triangle has it's center at where the height.
Also using Pythagora's Theorem we write, (where a is the length of a side of the triangle)
Next notice that every one of the little circles creates a new smaller triangle (look at the black line)
This new triangle has height $\frac{1}{3} h$ because it begins after the circle with
Now because of similar triangles theorem the small one is also equilateral meaning the
radius of the small circle is now $\frac{1}{3}$ of the new height therefore
We can continue the same logic for all the smaller circles and their radius will be