0
7.5kviews
A rectangle ABCD has vertices A(1,1), B(2,1), C(2,3), D(1,3). It has to be rotated by 300 CCW about point P(3,2). Determine(i) the composite transformation matrix (ii) the new coordinates of rectangle

Mumbai university > mechanical engineering > sem 7 > cad/cam/cae

Marks: 10 M

Year: May 2014

Difficulty: Medium

1 Answer
2
636views

enter image description here

Steps:

  1. Translate Point P(3,2) to origin O(0,0)
  2. Rotate the object by enter image description here
  3. Inverse translation of Point P to its original position P(3,2) from origin O(0,0)

Step 1:

Translation Matrix is given as:

enter image description here

Step 2:

Note: CCw is taken as +ve angle and CW is taken as –ve angle. Rotation Matrix is given as,

enter image description here

enter image description here

Step 3 :

enter image description here

Now,

i. The composite Transformation Matrix / Affine Matrix

enter image description here

ii. The new coordinates of rectangle

[X'] = [X] [T]

A' = A

B' = B

C' = C

D' = D

[T] = enter image description here

Hence, new coordinates of rectangle are :

A' = (1.77, 0.136)

B' = (2.36, 0.636)

C' = (1.63, 2.368)

D' = (0.77, 1.868)

Please log in to add an answer.