What is the name of this solid figure?

cylinder
rectangular prism
rectangular pyramid
triangular prism

Terri makes a quilt using three sizes of fabric squares the side lenght of each fabric square is the square root of the area

The nth term of a sequence in 2n-1 the nth term of a different sequence is 3n+1 work out 3 numbers that are in bothe sequences and are between 20 and 40

Which situation is an example of an observational study?