No. An isosceles trapezium (isosceles triangle with its apex removed) would have congruent diagonals but it is not a parallelogram.
None and no diagonals
Yes. An isosceles trapezium is like an isosceles triangle whose peak has been cut off by a line parallel to its base.
I think you might be thinking of a trapezium. A triangle with the top point sliced off by a line parallel to the base.
yes, because perpendicular lines always intersect. all lines intersect unless they are parallel or on separate planes (skew)
No. An isosceles trapezium (isosceles triangle with its apex removed) would have congruent diagonals but it is not a parallelogram.
The shape you are describing is a rhombus. A rhombus has two pairs of parallel sides, with opposite sides being equal in length. The diagonals of a rhombus are also equal in length, but they do not intersect at 90 degrees; instead, they intersect at a 90-degree angle.
None and no diagonals
A triangle has by definition three intersecting sides. If two of the sides are parallel, they will never intersect, so no triangle can ever be formed.
An isosceles trapezium has one pair of sides parallel to each other and the other pair that are of equal length (but facing in opposite directions). An isosceles trapezium can be imagined as an isosceles triangle whose top has been chopped off by a line parallel to its base.
Yes. An isosceles trapezium is like an isosceles triangle whose peak has been cut off by a line parallel to its base.
Suppose the base and parallel sides of the trapezium are labelled a and b. Suppose, also, that the distance between a and b is h. Draw a diagonal. This will split the trapezium into one triangle whose base is the trapezium's base (a) and another upside-down triangle whose base is the trapezium's top (b). The heights of both these triangles will be the same as the distance between the parallel sides of the trapezium (h). The area of the first triangle is 0.5*a*h The area of the second triangle is 0.5*b*h So the area of the trapezium = 0.5*a*h + 0.5*b*h = 0.5*(a+b)*h
none, the three sides meet so there are no parallel sides but all the sides are equal.
It's a quadrilateral (4 sides) and it has two sides that are parallel. If you draw a triangle and cut off one corner, you'll have two figures. One is a triangle, and the other, the 4-sided one, will be a trapezium.
none. A triangle, in standard 2 dimensions cannot have any parallel sides. Let's show without going into formal proof. Let's say that you try to make a triangle with 2 parallel sides. -------------side a------------- |C | | |side b | | |A -------------side c--------------- Side a & b intersect at vertex C. Side b & c intersect at vertex A, and since sides a & c are parallel, they will never intersect, so there is no third vertex, so it's not a polygon, much less a triangle.
I think you might be thinking of a trapezium. A triangle with the top point sliced off by a line parallel to the base.
yes, because perpendicular lines always intersect. all lines intersect unless they are parallel or on separate planes (skew)