Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫  π  -¹ ² ³ °

You are not logged in.

## #1 2012-10-23 21:48:05

Harold
Guest

### Rotation in graph

Suppose I have a triangle with coordinates (1,1),(3,1),(2,2) and I want to rotate them 80 degrees so that they stay at same distance from origin,what will be the rotated triangle's coordinates?how do I find them?

## #2 2012-10-23 21:54:52

bob bundy
Registered: 2010-06-20
Posts: 8,340

### Re: Rotation in graph

hi Harold,

Can you do matrix multiplication?

The matrix

multiplied by your coordinates written as vectors:

will do the trick.

MathsIsFun has a matrix calculator at

http://www.mathsisfun.com/algebra/matri … lator.html

Choose option AB.
Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

Offline

## #3 2012-10-23 22:08:27

Harold
Guest

### Re: Rotation in graph

Thank you,but i can do matrix multiplication and i have got my answer.