A plane mirror is inclined to the ground making an angle theta. A line is parallel to the ground and above it. On that line a light ray is incident at angle of 10°. Find the angle theta. Beware that the horizontal line drawn is not the normal to the ray.

Excel in math and science

Master concepts by solving fun, challenging problems.

It's hard to learn from lectures and videos

Learn more effectively through short, conceptual quizzes.

Our wiki is made for math and science

Master advanced concepts through explanations,
examples, and problems from the community.

Used and loved by 4 million people

Learn from a vibrant community of students and enthusiasts,
including olympiad champions, researchers, and professionals.

Your answer seems reasonable.
Find out if you're right!