So I thought I could solve my younger sister's Circle Puzzles.....

Aug 29, 2017 4:36 PM

So I thought I could solve my younger sister's Circle Puzzles.....

Recently started tutoring my little sister in maths thinking it would be a piece of cake with my whole Engineering background and all.... how wrong I was. Got tripped up on these 2 circles puzzles and have been at it for hours, can't admit defeat. Any help would be greatly appreciated and desperately needed. Please Reddit.. for the safety of my rep at home...

1. 1:2

8 years ago | Likes 2 Dislikes 0

Wow. What a circle jerk.

8 years ago | Likes 2 Dislikes 1

Hahaha

8 years ago | Likes 1 Dislikes 0

is.. is it 2.5 for the radius? Because the big circle has a diameter of 10 given it's exactly half as large, and following that logic, the

8 years ago | Likes 2 Dislikes 0

small circle looks about half as large as the big circle, so it has a diameter of 5..?

8 years ago | Likes 1 Dislikes 0

The semicircles' intersecting points form an equilateral triangle with sides of length R. Lines perpendicular to each side of the triangle 1

8 years ago | Likes 2 Dislikes 0

form 6 right triangles with long sides of length R/2. The short side of these right triangles is the radius of the small circle 2

8 years ago | Likes 1 Dislikes 0

Yeah... this turned out to be the way to do it. Diagram so counterintuitive though

8 years ago | Likes 1 Dislikes 0

So with 30-60-90 triangles, longside = short side * Sqrt(3)

8 years ago | Likes 1 Dislikes 0

So r=R/(2*√3)

8 years ago | Likes 1 Dislikes 0