A triangular banner has base 8 cm and vertical height 12 cm. How much cloth area is used?
Note
The cloth area is the triangle's area: 1/2 × 8 × 12 = 48 cm². A triangle is half of a rectangle or parallelogram with the same base and height, so we multiply by 1/2. Use the perpendicular height, not a slanted side, because the height must make a right angle with the base. The answer is in square units because area measures the surface covered by the triangle.
