Area of Triangles and Quadrilaterals Basic equations and applying to irregular polygons

Triangles Half the area of the Rectangle or parallelogram it would fit into Height or Altitude – perpendicular segment from vertex to side opposite, could be outside the triangle

Rectangles and Parallelograms These two go together because the are very similar shapes Base time height Remember the height is the perpendicular segment between two bases Rectangle – sides are perpendicular Parallelogram – need to have height or calculate the height, may be outside the parallelogram

Trapezoid Think of this as two triangles – they have different bases Sum of two bases times height divided by 2 Can’t always divide trapezoid into a rectangle and two triangles, the end triangles may not be the same

Kite Split into 2 congruent triangles using the diagonals Area of one triangle times 2

Example Find the area of the large rectangles and subtract the missing corner Divide shaded region into 2 rectangles Find the area of each rectangle and add Them together

Example Given the area find the base of the triangle Sub in what you know into the area Equation for a triangle and solve for b

Dotted lines represent heights of the same triangle but from different views. Look at the three triangles, they should all have the same area, set up area equation and solve for x and y

Homework All Homework Due Wednesday Pg odd, 17 and 20 Honors Pg odd Honors 18 and 19