Circumference of rectangle = (length+width) ×2C length =2(a+b) Area of rectangle = length× width S length = surface area of AB Cuboid = (length× width+length× height+width× height )× 2s length =2(ab+ah+bh) Volume of cuboid = length× width× height V length = Ah= bottom × height ÷ 2 = trapezoid area = (upper bottom+lower bottom) × height ÷2S step =(a+b) H÷2 circumference =2× pi × radius c circle =2πr= pi × diameter = area of pi circle = pi × radius 2S circle = π r 2 lateral area =2× pi × radius× height s side =2πrh= pi × diameter× height =πdh= +pi× diameter× height. 3× pi × radius 2× height V cone = 1/3 π r 2h trapezoid volume = (upper bottom+lower bottom )× height ÷2× height V step =(a+b)h÷2×h ring volume.