Answer: I. only
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Explanation :
II. False. a rectangle is a special type of rhombus since a rhombus has all sides equal, while a rectangle has all angles equal. A rhombus has opposite angles equal, while a rectangle has opposite sides equal.  The diagonals of a rhombus intersect at equal angles, while the diagonals of a rectangle are equal in length.
I.  True. A square is a special case of a rhombus, because it has four equal-length sides and goes above and beyond that to also have four right angles. Every square you see will be a rhombus, but not every rhombus you meet will be a square.
III. False.  Trapezoids have only one pair of parallel sides; parallelograms have two pairs of parallel sides. A trapezoid can never be a parallelogram. The correct answer is that all trapezoids are quadrilaterals.
 
        
             
        
        
        
Answer: Arithmetic 
Explanation: 
An Arithmetic Sequence is when a fixed amount is getting added on to the next term, which basically means it is adding a number at a constant rate.