Respuesta :

Answer: 6.4cm

Step-by-step explanation:

The area of a trapezoid is given as:

= 1/2(a + b)h

We then slot the given values into the formula. This will be:

1/2(15.8 + b) × 7.3 = 81.03.

7.3(15.8 + b)= 81.03 × 2

7.3(15.8 + b) = 162.06

115.34 + 7.3b = 162.06

7.3b = 162.06 - 115.34

7.3b = 46.72

b = 46.72/7.3

b = 6.4

Therefore, the answer is 6.4cm.