Remember the area of a triangle is (b)(h)(1/2). B is base and H is height. If you have difficulty remembering to divide by two remember that a triangle is half of a square and the area of a square is (b)(h).
1. 12 x 2 = 24/2 = 12 cm^2
2. 6 x 5 = 30/2 = 15 mm^2
3. 10 x 14 = 140/2 = 70 m^2
4. 8 x 12 = 96/2 = 48 cm^2
5. 8 x 9 = 72/2 = 36 mm^2