 Examples Parallelogram: A = b·h Triangle: 
Example 1: 
Here the height is one side of the triangleh = 12 cm b = 14 cm A = 0.5 x 14 x 12 A = 84 cm2 Example 2: Ignore any extraneous information you don't need. Just use the base and height: 
The base is 20 mm and the height is 9 mmA = b·h A = 20 x 9 A = 180 mm2 Example 3: Using 0.5 for the fraction ½ makes the calculator entry quicker.  b = 35 cm h = 24 cm A = 0.5 x 35 x 24 A = 420 cm2 Example 4: Finding a missing side when you know the answer: 
The area is 128 cm2. The base is 16 cm. Can we find the height h? A = b·h 128 = 16·h Divide both sides by 16: 8 cm = h |