Unit 10: 2-Dimensional Geometry

Area of Polygons

Area Formulas Square Area = side 2 Triangle Area = base × height 2 Trapezoid Area = height ×( base 1 + base 2 ) 2 Rectangle Area = length × width Rhombus Area = diagonal 1 × diagonal 2 2 Parallelogram Area = base × height These must be memorized!

Area of Squares & Rectangles Area = side 2 Area = (6) 2 Area = 36 square inches Rectangles Area = length × width Area = 8 × 3 Area = 24 square inches

Bases and heights must be at right angles! Area of Triangles Bases and heights must be at right angles! Right Triangle Area = base × height 2 Area = 2 × 4 2 Area = 8 2 Area = 4 square cm Triangle Area = base × height 2 Area = 6 × 4 2 Area = 24 2 Area = 12 square cm Triangle Area = base × height 2 Area = 3 × 5 2 Area = 15 2 Area = 7.5 square cm

Area of Parallelograms & Rhombi Area = base × height Area = 9 × 7 Area = 63 square inches Rhombus Area = diagonal 1 × diaagonal 2 2 Area = 12 × 8 2 Area = 96 2 Area = 48 square units

Area = height ×( base 1 + base 2 ) 2 Area of Trapezoids Trapezoid Area = height ×( base 1 + base 2 ) 2 Area = 5 ×(7 +13) 2 Area = 5 ×(20) 2 Area = 100 2 Area = 50 square inches