Question

draw a diagram in it​

Answer 1

Explanation:

From laws of reflection,

$< i1 > \: = \: < r1 > = 30 \\ in \: triangle \: abc \: \\ 0 = 180 - 90 - 60 = 30 \\ < i2 > = 30 \\ hence \: < r2 > = 60 \\ the \: angle \: of \: incidence \: is \: 60 \: degree$