11.1 Area of Parallelograms & Triangles HW pg. 723 #426 evens 1 March 24, 2014 11.1 Areas of Triangles & Parallelograms Objectives: 1. To develop the concept of area. 2. Apply area formulas to solve problems. Formula for: Area of a Rectangle: A = bh The base and height are always perpendicular to each other. What is area? Rules for Using Formulas: 1. Always state the formula you are using first! 2. Identify the knowns & unknowns for each variable in the formula. 3. Plug the knowns into the equation. 4. Solve for the unknown using algebra. 5. Be sure to include a label with your answer. A = _____ 10.5m 22m Find the area of the rectangle: 6m 12m 20m Area of a Parallelogram: A = bh The altitude will be perpendicular to the base. A = _____ Find the area of the parallelogram: Area of a Triangle = 1/2bh h b Find perimeter and area of the triangle. 8 17 10 21 P = 48 units A = 84 units 2 Base & height are always perpendicular to each other! Triangles can have multiple appearances: Find the height of the parallelogram. x 20 m Area = 100 m 2 Find the area of the rectangle. 18 m y Perimeter = 50 m