Question

Geometry classify triangles, I thought it was isosceles acute but was not

Answer 1

First of all, since 2 sides are same, we know that this is isosceles.

Now, is it isosceles,

acute?

right?

obtuse?

That depends on the angles.

If all 3 angles are less than 90, it is isosceles acute.

If there is 1 right angle, that is isosceles right.

If there is 1 angle greater than 90, that is isosceles obtuse.

Now, we see that this triangle has 1 angle that is 90 degrees.

So, this is isosceles right triangle.