This is an important question from the
Book- ML Aggarwal
Chapter- Trigonometric Identities
If x = h + a cos θ and y = k + a sin θ, prove that (x – h)2 + (y – k)2 = a2.
Trigonometric Identities, class 10th, chapter 18th, question no 35, ICSE board, ML aggarwal..