How do you find the area of a tringle with 3 sides

For the sequence [tex]a_{n} = 2n/(n+1)[/tex], what is the value of [tex]a_{10}[/tex]

Tim knows the volume and base area of a wooden chest that is in the shape of a rectangular prism. if the volume is 524 cubic unit and the base area is 15 square unit, what is the height of the chest? 124 unit 1124 units 112 unit 1112 units

Henry's butcher shop uses an electronic scale that measures to 1/100 of a pound. which is the most accurate measurement based on the limitations of the scale that might be found on a package of meat sold by henry?