1. find the perimeter and area of triangles and trapezoids.
Goal: I will be able to
find the perimeter and area of triangles
and trapezoids.
Tool Bag
Formulas, equations,
Vocabulary, etc.
Here’s How…Notes & Examples
Standard MG 2.1 – Use formulas to find perimeter and area of basic two-dimensional figures
Example #1
find the perimeter of the trapezoid: 14 8 8 10
Perimeter = P =
= 40
Example #2
find the area of the following triangle:
Area of a parallelogram = b • h
Two Triangles make the parallelogram h
Area of 1 Triangle = ½ area of parallelogram b
Area of Triangle = ½ b • h

2. find the perimeter and area of the following triangle:
You Try
find the perimeter and area of the following triangle: 10 10 6 16
Example #3
find the area of the following trapezoid: b 2 b 1 h b 1 b 2
Area of a parallelogram = b • h
Area of a parallelogram = ( ) • h b 1 2
Area of a trapezoid = ½ ( ) • h b 1 2
You Try
find the area of the following trapezoid: 16 6 12

3. For any right triangle, the sides are related as follows:
Pythagorean
Theorem
For any right triangle, the sides are related as follows: c a b
Example #4
find the missing side of the following triangles: x 12 5
You Try
find the missing side of the following triangles: a) b) x 4 3 10 8 x