When a ray strikes concave or convex mirrors obliquely at its pole. It's forming straight angle right angle obtuse angle acute angle

Straight Angle.

Explanation:

The two types of mirrors, i.e., concave mirror and convex mirror, acts in the same way when a ray is directed towards its pole, and the ray bounces back with the same intensity, and we get the exact same angle.

And, the initial angle and the reflected angle are exactly the same.

Hence, when the ray strikes the pole, in straight angle, then it forms a straight angle.

Hence, from the given option,

The correct answer is straight angle.

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.