Formulas for Geometry Powerpoint （公式的几何幻灯片）.pptVIP

Free powerpoint template: Formulas for Geometry Mr. Ryan Don’t Get Scared!!! Evil mathematicians have created formulas to save you time. But, they always change the letters of the formulas to scare you! Perimeter Any shape’s “perimeter” is the outside of the shape…like a fence around a yard. Perimeter To calculate the perimeter of any shape, just add up “each” line segment of the “fence”. Perimeter Triangles have 3 sides…add up each sides length. Perimeter A square has 4 sides of a fence Perimeter Sometimes, problems may only give you two measurements for a square or rectangle. No problem…use the formula for squares/rectangles (only!) Remember Squares ALL sides are equal…so if they give you one side, you know ALL the sides Length=the Largest side If they “leave” numbers out, they are equal to their opposite side. If they give you the bottom of a square/rectangle type shape then the top is the same The Same!! If the bottom is 15…the top is… Square/Rectangle Formula Perimeter=2(Length+Width) P= 2(25+14) P=2(20+20) P= 50+28 P=40+40 P= 78 P=80 Other shapes Just add up EACH segment Odd shapes Count ALL sides Remember if one side blank, it’s equal to its opposite Area Area is the ENTIRE INSIDE of a shape It is always measured in “squares” (sq. inch, sq ft) AREA Square units means that “that” many squares fit inside that shape (if measured in feet…it’s feet…if meters…it’s meters. In this example the area is 4 square units…note 4 squares fit) Area of Squares/Rectangles Length x Width=Area Parallelogram Area Same idea as squares rectangles, but they change the words to Base (length:bottom of shape) and height (width) Parallelogram Area Area=Base x Height (Area=length x width) REAL formula for area of squares Area= S^2 Area= Side x Side (side squared) (just a different way of saying length x width) Different Names/Same idea Length x Width = Area Side x Side = Area Base x Height = Area Area of a Triangle ? Base x Height = Area (It