1.4 Introduction to Perimeter, and Area in the coordinate plane. Geometry 1.4 Introduction to Perimeter, and Area in the coordinate plane.

Geometry 1.4 Perimeter, Area Topic/Objectives: Find the perimeter and area of common plane figures. To classify polygons. To compare convex and concave polygons. May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Square Perimeter P = 4s S S Area A = s2 May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Square Problem Each side of a square measures 2.5 m. Find its perimeter and its area. P = 4(2.5) = 10 m A = 2.52 = 6.25 m2 2.5 m 2.5 m Area is a square measure. May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Rectangle Perimeter P = 2 l + 2w w Area A = lw l May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Rectangle Problem Find the perimeter and the area. 4 ft 2.1 ft P = 2(4) + 2(2.1) = 8 + 4.2 = 12.2 ft A = 4(2.1) = 8.4 ft2 May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Triangle Perimeter P = a + b + c c a h Area b May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Triangle Problem Find the perimeter and the area. 8 in 3 in 2 in 10 in P = 3 + 10 + 8 = 21 in A = ½ (10)(2) = 10 in2 May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Problem Solving Steps Sketch Label Formulas Reason Conclusion Check May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Problem 1 A homeowner needs to fertilize a rectangular shaped yard that measures 20 ft by 30 ft. Each bag of fertilizer covers 150 square feet. How many bags of fertilizer will he need? 1. Sketch 2. label 30 ft. A = ? 20 ft May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Problem 1 Continued A homeowner needs to fertilize a rectangular shaped yard that measures 20 ft by 30 ft. Each bag of fertilizer covers 150 square feet. How many bags of fertilizer will he need? 3. Formula: A = LW a = 30(20) = 600 FT2 30 ft. A = ? 20 ft May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Problem 1 Continued A homeowner needs to fertilize a rectangular shaped yard that measures 20 ft by 30 ft. Each bag of fertilizer covers 150 square feet. How many bags of fertilizer will he need? 4. Reason: Each bag covers 150 sq ft, and he needs to cover 600 sq ft. 600  150 = 4 30 ft. 20 ft A = 600 FT2 May 25, 2018 Geometry 1.4 Perimeter, Area

Problem 1 Conclusion A homeowner needs to fertilize a rectangular shaped yard that measures 20 ft by 30 ft. Each bag of fertilizer covers 150 square feet. How many bags of fertilizer will he need? 5. Conclusion: He needs to buy 4 bags of fertilizer. 30 ft. 6. Check: 4  150 = 600 20 ft A = 600 FT2 May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area EX: Determine the perimeter of the polygon with the given vertices. A(-4,-1), B(1,4), C(4,1),D(-1, -4) B Sketch Label C A   D Formulas: Use distant formula to find each length.   May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area EX: Find the area of the polygon with the given vertices. (-2,3),(3,-3),(-2,-3) A = ½ bh   6 A = 15 5 May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Convex vs Concave May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Problem 2 You are making a mat for a picture. The picture is 8 inches wide and 10 inches high. The mat is to have a width of 2 inches. What is the area of the mat? 8 2 10 2 May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Problem 2 Continued You are making a mat for a picture. The picture is 8 inches wide and 10 inches high. The mat is to have a width of 2 inches. What is the area of the mat? Think: Larger mat, cut away the inside… May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Problem 2 Continued You are making a mat for a picture. The picture is 8 inches wide and 10 inches high. The mat is to have a width of 2 inches. What is the area of the mat? We need to know the area of the outer rectangle. 12 Left over Area = 168 – 80 = 88 in2 Outer Area = 12  14 = 168 8 14 2 10 Inner Area = 8  10 = 80 2 May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Problem 3: You do it. You are making a triangular shaped window. The height of the window is 18 inches and the area will be 297 square inches. What will the length of the base of the window be? 18 b The base will be 33 in. May 25, 2018 Geometry 1.4 Perimeter, Area

Geometry 1.4 Perimeter, Area Write a Summary May 25, 2018 Geometry 1.4 Perimeter, Area