# Rotate 90 degrees Counterclockwise or 270 degrees clockwise about the origin

Earlier we learned about 90 degrees clockwise rotation, and now we are going to talk about 90 degrees counterclockwise rotation.

Before we go ahead and explain, please note that

90 degrees counterclockwise and 270 degrees clockwise are the same thingsand you need to use the same formula for both.

## What is the Formula to find out 90 degrees Counterclockwise rotations

We swap the value of x and y and negate the value of y. So the value of x becomes the value of y and value of y becomes the value of x. so the formula is:

(x, y) –> (-y, x)

Before Rotation |
After Rotation |

(x, y) | (-y, x) |

**Question:** Rotate 90 degrees counterclockwise about the origin **C(2,1), B(3,7), and A(-5,6)**

**Calculation Explanation: The Rule we used to get value**

Applying (x, y) –> (-y, x) formula to all values to get the new value.

Before Rotation |
After Rotation |

C(2,1) | C'(-1,2) |

B(3,7) | B'(-7,3) |

A(-5,6) | A'(-6,-5) |