Answer:
1. isosceles trapezoid- a trapezoid that has two congruent sides (other than the bases)
2. triangle- a polygon with three sides
3. line symmetry- property where a figure can be folded along a line to create two congruent mirror images
4. line of symmetry- the line which divides a figure into two congruent mirror images
5. rotational symmetry- property where a figure can be rotated less than 360° and still look the same
6. trapezoid- a quadrilateral with one pair of parallel sides
 
        
             
        
        
        
Answer:
 good morning :) 
the answer is 15 
Step-by-step explanation:
because jayda found 5 and ruby found twice as her which means he found 10 and all they are asking you to do is add jayda's and ruby's sheashells togather 
hope this helps <333
brainliest plz? :)
 
        
             
        
        
        
Your answer would be -18m-6n-30