If a pair of triangular plates are stacked as shown in the figure, the degree of angle α is______ .

If a pair of triangular plates are stacked as shown in the figure, the degree of angle α is______ .

∵ in the figure, there is a pair of triangle plate, ∵ 2 = 45 °, 1 = 90-45 ° = 45 °, α = ∵ 1 + 30 ° = 45 ° + 30 ° = 75 °. So the answer is: 75 °