How do I find the missing length?

Find the area of an equilateral triangle with a side of 6 inches

Tim has obtained a 3/27 balloon mortgage. after the initial period, he decided to refinance the balloon payment with a new 30-year mortgage. how many years will he be paying for his mortgage in total?

The volume of a rectangular prism is found by multiplying the length, width, and height of the prism. a rectangular prism has a width of 5x^2units, a length of 7x^3 units and a height of 2x^4 units. which is the volume of the prism in terms of x?