A = 1/2h(b1+b2)

Multiply both sides by 2

2A = h(b1+b2)

Multiply both sides by 1/h

2A/h = b1+b2

Add -b1 to both sides

2A/h + -b1 = b2

**Answer:**

**b2 = 2A/h - b1**

A = 1/2h(b1+b2)

Multiply both sides by 2

2A = h(b1+b2)

Multiply both sides by 1/h

2A/h = b1+b2

Add -b1 to both sides

2A/h + -b1 = b2

**Answer:**

**b2 = 2A/h - b1**