Series of answers to the practice and exploration of the new mathematics curriculum in the second volume of the seventh grade

According to the maximum value of the angle B, if the angle A is 3 = 5, the inequality groups can be listed.

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.