Daniel used the formula to find the area of the following special trapezoid. His work is shown. Identify his error and correct i
t to find the area of the special trapezoid. \(\text{Line}\ 1:\ A=\frac{1}{2}\left(6\right)\left(7+7\right)\) \(\text{Line}\ 2:\ A=\frac{1}{2}\left(6\right)\left(14\right)\) \(\text{Line}\ 3:\ A=\left(3\right)\left(7\right)\) \(\text{Line}\ 4:\ A=21\text{ cm}^2\)
