Answer:
see below
Explanation:
1. If one of the angles is 140 degrees, that is greater than 90 degrees, which makes it obtuse
Two of the sides are equal, which makes it isosceles
The triangle is isosceles obtuse
2. All triangles are plane figures true because they are 2 dimensional.
All triangles have 3 angles. true Triangles have 3 sides and 3 angles
All triangles have 3 straight sides. true Triangles have 3 sides and 3 angles
False, triangles do not have to have a right angle
False, all triangles are polygons. They are 3 sided closed figures
3. To be an acute triangle, all angles must be acute
exactly three acute angles - true
polygon - true
exactly one acute angle - false (they all must be acute)
exactly 2 acute angles false ( they all must be acute)
one right angle false (they all must be acute)
3 straight sides true Triangles have 3 sides and 3 angles