Question

A triangle with vertices at A (20, -30), B (10, -15) and C (5, -20) has been dialted with a center of dialation at the origin. The image of B, point B' has the coordinates (2, -3). What is the scale factor of the dilation?

Answer 1

Scale factor: 1.8

Explanation:

AB' = √(20-2)² + (-30 - -3)² = √1053 = 9 √13

AB = √(20-10)² + (-30 - -15)² = √325 = 5 √13

AB' / AB = 9 √13 / 5 √13 = 9/5 = 1.8