A Beam of Light Traveling in Air Strikes a Slab $40 ^ { \circ }$

A beam of light traveling in air strikes a slab of transparent material. The incident beam makes an angle of $40 ^ { \circ }$ with the normal, and the refracted beam make an angle of $26 ^ { \circ }$ with the normal. What is the speed of light in the transparent material? $\left( c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$

A) $1.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$
B) $2.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$
C) $3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$
D) $0.50 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$
E) $2.3 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$