Hey there! I'm happy to help!
A quadrilateral is any polygon (enclosed shape) with four sides. Let's see what each of these shapes are.
- Scalene right triangle - the prefix tri- means three (tricycle, tripod, triple, etc.), and all triangles have three sides, so this is not a quadrilateral.
- Obtuse scalene triangle - once again a triangle, so not a quadrilateral.
- Isosceles right triangle - would you look at that, another triangle! Not a quadrilateral.
- Hexagon - a hexagon is a six-sided polygon (hex=six), so this is not a quadrilateral.
- Pentagon - a pentagon is a five-sided polygon (pent=five, like Pentatonix!). Not a quadrilateral
- Right trapezoid - a trapezoid is a quadrilateral with at least one pair of parallel sides!
- Venn diagram - a Venn diagram is a compare and contrast chart made of two overlapping circles (ZERO sides), so this is not a quadrilateral.
So, the only shape on your list that is a quadrilateral is 6. right trapezoid.
Have a wonderful day! :D
