Write a formula for the given quanity. 1.the perimeter p of a rectangle with base b and height h. 2. the nth odd number,0 (1 is the first odd number,3is the second odd number and so on) 3.the area a of a triangle with base b and height h

1.) Perimeter of rectangle with base B and Height H.

Perimeter =  2*(Base + Height)
 
               =  2*(B + H)

2.) Nth odd number.
Odd number sequence = 1, 3, 5, 7, 9, 11,
                                                             (2n + 1)
zeroth, 0th, odd number = 1                    2*0 + 1 = 1    
1st odd number = 3                                2*1 + 1 = 3
2nd odd number = 5                               2*2 + 1 = 5
3rd odd number = 7                                2*3 + 1 = 7
4th odd number = 9                                2*4 + 1 = 9

And so on.   So the nth odd number starting from 0 is  = 2n + 1.
                  
3.) Area of triangle with Base B and Height H

    Area = (1/2)*B*H  = (1/2)BH

Arhombus is a quadrilateral.