By Affine Transformation the Ellipse to a Circle, the corresponding ratios preserved. Hence it is easier to prove in the circle below:
Similar triangles CQV ~ CTQ
数学中的冷知识：圆幂定理，现在初中课本中都不讲了，但是非常有趣?
圆幂 定理 II: The Affine Transformation FROM Circle to Ellipse. Also applicable to all other 2 Theorems.
https://m.toutiaoimg.cn/a6580683485986423309
Proof : Ellipse Area from Circle :
