yes, a triangle is a closed figure
A scalene triangle.
An obtuse triangle whose other two angles will be acute angles
Not always, there could be an obtuse triangle but that won't be turned into a four sided figure
Starting with the definition of polygon makes much easier to understand why triangle is a polygon.Definition: A polygon is a closed figure bounded by sides.Definition of triangle: Triangle is a closed figure bounded by three sides.Since triangle is also a closed figure bounded by sides therefore, triangle is a polygon.
an obtuse triangle
A polygon is a closed figure bounded by sides. A triangle is a closed figure bounded by three sides. Therefore, according to the definition of polygon triangle is a polygon.
obtuse triangle
no.
yes
An obtuse triangle has an obtuse angle.
An oxymoron. An equilateral triangle cannot be obtuse; an obtuse triangle cannot be equilateral.