Triangle abc is an abtuse triangle with the abtuse angle at vertex b. angle a must be : less than 90 greater than 90. congruent to angle b congruent to angle c

If angle B of the triangle is obtuse, the two remaining angles, A and C, must both be acute--less than 90°. They are not necessarily congruent.

The 1st selection is the correct one: Angle A must be less than 90°.

Yeah she/ he needs look how long that is man