Answer:
No. There can be an obtuse angle or a right-angle in an isosceles triangle.
Step-by-step explanation:
Explanation:
No. You can three types of isosceles triangles:
acute-angled isosceles triangle
All the angles are acute and the base angles are equal.
eg:
75 ° , 75 ° , 30 °
or
50 ° , 50 ° , 80 °
right-angled isosceles triangle
One angle is 90 ° and the other two are both 45 °
45 ° , 45 ° , 90 °
←
(like one of the usual set squares)
obtuse-angles isosceles triangle
One angle is obtuse and the base angles are equal.
eg:
30 ° , 30 ° , 120 °
or
25 ° , 25 ° , 130 °
Ofcourse there can only be one 90 °
or
one obtuse angle in a triangle. The other two angles MUST be acute, else the sum would be more than 180 °