Yes, an obtuse triangle can be isosceles. An obtuse triangle is defined as a triangle with one angle greater than 90 degrees. An isosceles triangle, on the other hand, has at least two sides that are equal in length, which also means it has two equal angles.
To visualize this, imagine a triangle where two sides are of equal length, and the angle between these two sides is greater than 90 degrees. The other two angles will be acute (less than 90 degrees) and equal in measure. This configuration satisfies both the conditions of being obtuse and isosceles.
Here’s a simple example:
- Side A = 5 units
- Side B = 5 units
- Side C = 8 units
In this triangle, sides A and B are equal, making it isosceles. The angle opposite side C (the longest side) will be greater than 90 degrees, making it obtuse.