Area of a... Trapezoid!

Area of a... Trapezoid!

What is it?? • What is a trapezoid and what do we know about it? • A quadrilateral with at least one pair of parallel sides • Why are rectangles, squares and parallelograms, trapezoids? • Knowing what we know about each shape, (including triangles), how might we find the area of a trapezoid?

There Are 4 Different Ways to Find the Area of a Trapezoid: 2 Triangles & rectangle Parallelogram & 1 Triangle 2 Triangles Formula

An Explanation... A = (bh) + (bh) 2 2 = (bh) + (bh) 2 = (b + b) x h 2 = (a + b) x h 2 But in a trapezoid, there are 2 different sized bases, so we label them differently

There Are 4 Different Ways to Find the Area of a Trapezoid: 2 Triangles & rectangle Parallelogram & 1 Triangle 2 Triangles Formula A = (a + b) x h 2

Example: 2 Triangles & Rectangle 9m 4m 2m 9m 1m A Trapezoid = A + A + A =(bh) + bh + (bh) 2 2 =()+( )+() 2 2 =()+( )+() 2 2 =2m2 + 36m2 + 4m2 =42m2 1m x 4m 2m x 4m 9m x 4m 36m2 8m2 4m2

Example: Parallelogram & Triangles 9m 4m 3m 9m A Trapezoid = A + A =(bh) + bh 2 =()+( ) 2 =()+( ) 2 =6m2 + 36m2 =42m2 3m x 4m 9m x 4m 12m2 36m2

Example: 2 Triangles 9m 4m 12m A Trapezoid = A + A =(bh) + (bh) 2 2 =()+() 2 2 =()+() 2 2 =24m2 + 18m2 =42m2 12m x 4m 9m x 4m 48m2 36m2

Using the Formula! 9m 4m 12m • A = (a + b) x h 2 = ( ) x ( ) 2 = ( ) x ( ) 2 = 84cm2 2 = 42cm2 4m 9m + 12m 21m 4m

Homework: • # 1 – 8 & Reflection

Area of a... Trapezoid!