The height of a triangle is 1 cm less than twice the length of the base. let x = the length of the base. write a function rule for the area of the triangle and determine the area if the length of its base is 16 cm. a. a=12x(2x−1); 248cm2 b. a=12xh; 128cm2 c. a=12x(x−2); 112cm2 d. a=122x(x−1); 240cm2