Is a triangle a plane shape?

Hint: First we will understand the term ‘plane shape’ and then we will understand about the shape triangle see the diagram of a triangle with its common properties. Further, we will check if the triangle can be called a plane shape by matching their properties to conclude the answer.

Complete step-by-step solution:
Here we have been asked if we can say that a triangle can be called a plane shape or not. First we need to understand the term ‘plane shape‘, then check if the triangle satisfies the criteria to be called a plane shape or not.
If all the parts of a shape can be drawn on a single plane (neither above nor below the plane) then that shape is called a plane shape. Now, a triangle is a 2 – dimensional shape that has three sides, three angles and three vertices. We can draw a triangle with all its parts lying on a single plane that can be shown as below,

Hence, we can conclude the statement that ‘a triangle is a plane shape’.

Note: Note that all the 2 – dimensional shapes like circle, square, rectangle, parallelogram etc. can be considered as plane shapes. No matter how a 2 – dimensional shape is present in space there will always be a particular plane which will contain all the parts of the shape. On the other hand, 3 – dimensional shapes like cube, cuboid, cone, cylinder etc. are known as solid shapes.