Chapter 9 - Transformations

Chapter 9 - Transformations

90 degree rotation(x1, y1)

180 degree rotation(x2, y2)

270 degree rotation(x3, y3)

9.3 - Rotations (notation)

• Correct Notation = r (angle, point) {object}

• r(90, O) ABCD This “rotates” the quadrilateral ABCD an angle of 90 degrees counter-clockwise around the origin.

• r(180, O) ABCD This “rotates” the quadrilateral ABCD an angle of 180 degrees counter-clockwise around the origin.

Section 9.3 – Rotation Rules

Section 9.3 – Rotation Rules

Rotating an Object around the Origin

r(90,O) ABC

x

yScale is 1 by 1

A

B C

A’B’

C’

r(180,O) ABC

r(270,O) ABCA”

B”C”

A’’’B’’’

C’’’