Can the angles at the base of an isosceles triangle be straight or obtuse?

The answer to this question lies in the name of the figure itself.

Triangle – This means the shape has 3 corners. Not 4 and not 5.

If the corners at the base are straight, then in the end we get a square or rectangle. A triangle cannot be formed at such angles.

If the corners are obtuse, you get a trapezoid. this is also not a triangle.

In addition, the angles in the triangle add up to 180 °.

The right angle is 90 °, and the obtuse angle is even more.

So with straight and obtuse angles you can’t get 180 °.