3 angle A = 5° angle b

3 angle c ≤ 2 angle b

Angle A+ angle B+ angle C = 180.

Angle b = 43.2 degrees.

Angle c = 28.8

Set according to the maximum value of angle b.

∴ It should be angle b < 43.2 and angle c ≤ 28.8.

∴ angle b+ angle c < 90.

∴ Angle α > 90.

The triangle should be obtuse.