Area of Composite Shapes We are learning to…find the area of composite shapes (shapes made up of more than one figure). Monday, September 07, 2015

Area of Composite Shapes Review of Important Area Formulas Area of a Rectangle: A = b(h) Area of a Triangle: A = ½(b)(h) Area of a Circle: A = π r 2 Area of a Parallelogram: A = b(h) Area of a Trapezoid: A = ½(b 1 + b 2 )h

Area of Composite Shapes Example #1: Find the area of the composite shape below. 10 feet 4 feet Plan: Area of a Rectangle + Area of ½ Circle l(w) + ½ π r 2 4(10) + ½ π (2) 2 Diameter = 4 feet Radius = 2 feet 4(10) + ½ π (4) 40 + ½ π (4) 40 + (1.57)(4) square feet

Area of Composite Shapes Example #2: Find the area of the shaded region. Plan: Area of a Square - Area of Circle l(w) - π r 2 4(4) - π (2) 2 4(4) - π (4) 16 - π (4) square cm 4 cm

Area of Composite Shapes Example #3: Find the area of the shaded region. Plan: Area of a Trapezoid - Area of a Triangle ½(b 1 + b 2 )(h) - ½(b)(h) ½(18)(4) - ½(6)(4) 6 in 5 in 4 in 12 in ½(6 + 12)(4) - ½(6)(4) 36 - ½(6)(4) square inches

Area of Composite Shapes Example #4: Find the area of the shaded region. Plan: Area of a Trapezoid - Area of a Circle ½(b 1 + b 2 )(h) - π r 2 ½(21)(8) - π (4) 2 ½(6 + 15)(8) - π (4) 2 ½(21)(8) - π (16) 84 - π (16) square feet 8 ft 15 ft 6 ft 10 ft 84 – 50.24

Area of Composite Shapes Example #5: Find the area of the polygon below. Plan: Area of a Rectangle + Area of a Rectangle l(w) + lw (20) 9(13) + 5(20) Square inches 18 in 5 in 11 inches 9 inches 18 – 5 = 13 inches = 20 inches

Individual Practice Try the last example with your team! When you are done raise your hand and show your teacher the solution.