Q:

1 Ye Li drew a quadrilateral that is both a rectangle and a rhombus name the quadrilateral and describe it using the properties of sides and angles2 Yes or no. A rhombus is a trapezoid A parallelogram has exactly 1 pair of parallel sidesA rectangle is also a rhombusA rectangle is also a parallelogram3 What quadrilateral is NOT a parallelogram RhombusSquareRectangleTrapezoid4 Sometimes,Always,NeverEquilateral triangles are ____ Acute trianglesScalene triangles are ____ acute trianglesRight triangles are ______ acute trianglesObtuse triangles are____ isosceles triangles

Accepted Solution

A:
1. Let's start with the properties of the geometric terms you were given. 
Quadrilateral - a four-sided figureRectangle - four sides, two pairs of opposite sides are parallel, four right anglesRhombus - four sides, two pairs of opposite sides are parallel, all sides equal
We're looking for a shape that has four sides that are all equal, has two pairs of parallel sides, and has four right angles. The shape that fits what Ye Li drew is a square. Squares have two pairs of parallel sides (like a rhombus and rectangle), four right angles (like rectangles), and four sides that are equal (like a rhombus). A square is both a rectangle and a rhombus.

2. A rhombus is a trapezoid. No
Above we defined what a rhombus is. A trapezoid is a quadrilateral with only one pair of parallel sides. A rhombus has two pairs of parallel sides and is not a trapezoid.

A parallelogram has exactly 1 pair of parallel sides. No
By definition, a parallelogram has two parallel pairs of opposite sides. 

A rectangle is also a rhombus. Yes
As long as the rectangle is a square, then it can also be a rhombus.

A rectangle is also a parallelogram. Yes
Parallelograms have two parallel pairs of opposite sites. The same is true of rectangles.

3. A parallelogram has two pairs of parallel sides. A rhombus, square, and rectangle all fit this description. However, a trapezoid does not because it only has one pair of parallel sides. Trapezoid is the answer.

4. For this question, we're looking at identifying triangles by their sides and angles.
Equilateral triangles are those with three sides that all have the same length.
Scalene triangles have three unequal sides.
Isosceles triangles have at least two equal sides.
Acute triangles have three angles that are acute (less than 90°).
Right triangles have an angle that is 90°.
Obtuse triangles have an angle that is obtuse (greater than 90°).

Equilateral triangles are always acute triangles.
All angles of an equilateral triangle are less than 90° and all angles are equal.

Scalene triangles are sometimes acute triangles.
Triangles that have three sides that are all different may sometimes also have acute angles, but not always. 

Right triangles are never acute triangles.
Acute triangles have three angles that are all acute. If a triangle has a 90° angle then it cannot have three acute angles.

Obtuse triangles are sometimes isosceles triangles.
Two sides of a triangle can be the same length with one obtuse angle.