which of the following triangles is both an obtuse triangle and isosceles triangle.
A triangle with angles measuring:
a) 60,60,60
b) 120,30,30
c) 110,15,55
d) 30,70,80
An Isosceles triangle has 3 equal angles. so the ans. is b.
CORRECTION: 2 EQUAL ANGLES.
To determine if a triangle is obtuse, we need to identify if any of its angles are greater than 90 degrees. To determine if a triangle is isosceles, we need to determine if any two sides of the triangle are equal in length.
Let's evaluate each option:
a) 60, 60, 60: This triangle has three equal angles, which means it is an equilateral triangle. Therefore, it is not obtuse nor isosceles.
b) 120, 30, 30: This triangle has one angle greater than 90 degrees (120 degrees) and two equal angles (30 degrees each). Therefore, it is an obtuse triangle. However, it is not isosceles because none of its sides are equal in length.
c) 110, 15, 55: This triangle does not have any angle greater than 90 degrees, so it is not obtuse. It also does not have any two sides equal in length, so it is not isosceles.
d) 30, 70, 80: This triangle does not have any angle greater than 90 degrees, so it is not obtuse. However, it does have two sides (70 and 80) that are equal in length, making it an isosceles triangle.
Therefore, the correct answer is (d) 30, 70, 80.