A square or a rectangle perhaps?
Not always because a quadrilateral is any 4 sided shape.
Never, there are no true "opposite sides" on a triangle as each side intersects the other two at a point. Were two of the lines parallel, the triangle would be missing a point and would not be a closed shape.
it just doesnt exist. parallelogram is a closed shape vth opposite sides parallel adjacent angle not 90 degree. triangle is closed shape vth 3 sides.
An octahedron is a closed 3-d shape with 8 polygonal faces. There are 257 topologically different convex octahedra. One of these 257 shapes is a prismoid, and a prism is a special case of a prismoid in which the two hexagonal faces are congruent and parallel.
Opposite sides are parallel, Consecutive angles are supplementary, Opposite angles are congruent, Opposite sides are congruent (APEX)
A square or a rectangle perhaps?
Not always because a quadrilateral is any 4 sided shape.
The answer would be a right cylinder. A right cylinder is a cylinder that has a closed circular surface having two parallel bases on both the ends and whose elements are perpendicular to its base.
Never, there are no true "opposite sides" on a triangle as each side intersects the other two at a point. Were two of the lines parallel, the triangle would be missing a point and would not be a closed shape.
The opposite of the adjective closed is open. The opposite of the verb closed is opened.
A rectangle has four sides and four angles. A rectangle is a closed shape. All four angles of a rectangle are right angles. That is, they are 90 degrees. Opposite sides of a rectangle are the same length. Opposite sides of a rectangle are parallel. That is, if they were extended infinitely they wouldn't touch. ***Additionally, the diagonals of a rectangle are congruent (unlike other parallelograms), and they also bisect each other. While all parallelograms share the bisecting diagonals characteristic, only rectangles (and by extension squares) have congruent diagonals.***
A quadrilateral is a four-sided polygon (closed shape made with line segments). Quadrilaterals have four angles (vertices) and come in many different shapes, depending on the length of their sides and the kinds of angles they have. The five most common quadrilaterals are the rectangle, square, parallelogram, rhombus, and trapezoid. A rectangle is a quadrilateral with opposite sides congruent (same length) and parallel. It has four right (90º) angles. A square has ALL four sides that are congruent, and two pairs of parallel sides. It also has four right angles. A parallelogram has two pairs of parallel sides. They form two acute and two obtuse angles. A rhombus has two pairs of parallel sides, but all sides are congruent. They also form two acute and two obtuse angles. Finally, a trapezoid, has only one pair of parallel sides. The parallel sides are NOT congruent. A trapezoid can be formed by two acute and two obtuse angles, or by two right angles, one acute, and one obtuse angle.
The opposite of the adjective closed is open. The opposite of the verb closed is opened.
it just doesnt exist. parallelogram is a closed shape vth opposite sides parallel adjacent angle not 90 degree. triangle is closed shape vth 3 sides.
no.
A scalene triangle has no sides congruent.