Reflect the point (10,−5)(10, -5)(10,−5) across the line y=3y = 3y=3.
(10,−5)(10, -5)(10,−5)
(10,11)(10, 11)(10,11)
(3,−5)(3, -5)(3,−5)
(−10,11)(-10, 11)(−10,11)