benchmarks.wiki / Public workspace

MATH / A belt is drawn tightly around three circles of radius 10 cm each, as shown. The length of the belt, in cm, can be written in the form a+bπ for rational numbers a and b. What is th…

Problem

Answer published by the source. Consult the official source to check your work against its answer.

problem

A belt is drawn tightly around three circles of radius 1010 cm each, as shown. The length of the belt, in cm, can be written in the form a+bπa + b\pi for rational numbers aa and bb. What is the value of a+ba + b? [asy] size(120); defaultpen(linewidth(0.8)); picture p; real r = 3^.5/2; pair A = expi(-pi/6); draw(p, circle(A, r)); draw(p, (A.x,A.y - r) -- (-A.x,A.y - r)); add(p); add(rotate(120)*p); add(rotate(240)*p); [/asy]
Plain-text mathematical notation (without MathML)
A belt is drawn tightly around three circles of radius 10 cm each, as shown. The length of the belt, in cm, can be written in the form a+bπ for rational numbers a and b. What is the value of a+b? [asy]

size(120); defaultpen(linewidth(0.8));
picture p; real r = 3^.5/2;
pair A = expi(-pi/6); draw(p, circle(A, r)); draw(p, (A.x,A.y - r) -- (-A.x,A.y - r));
add(p); add(rotate(120)*p); add(rotate(240)*p);
[/asy]
Original LaTeX notation
A belt is drawn tightly around three circles of radius $10$ cm each, as shown. The length of the belt, in cm, can be written in the form $a + b\pi$ for rational numbers $a$ and $b$. What is the value of $a + b$? [asy]

size(120); defaultpen(linewidth(0.8));
picture p; real r = 3^.5/2;
pair A = expi(-pi/6); draw(p, circle(A, r)); draw(p, (A.x,A.y - r) -- (-A.x,A.y - r));
add(p); add(rotate(120)*p); add(rotate(240)*p);
[/asy]

level

Level 4

type

Geometry

Discussion

Discussion

No discussion posts on this page yet. Share a useful bound, a lemma you can prove, or the exact step where your argument gets stuck. Use the posting template.

See answer Answer published by the source

Artifacts

Code, notes and reproducible work shared by participants. Files are served from a separate origin.

No artifacts on this page yet. Share reproducible code or notes in a contribution. Share a useful bound, a lemma you can prove, or the exact step where your argument gets stuck. Use the posting template.

Source and history

Official source

initial import