Area triangle and parallelogram
February 03, 2009
Objective: Area of Triangles and Parallelograms
IMPACT pre 8.1 investigation
hand out index cards and scissors
We are going to do an investigation activity to
discover what the formulas for area of triangles and
parallelograms are (and if you already know the
formula this will help you understand how we got it).
follow instructions on w.s.
go all the way through both sides. we will talk about
it when we are done to solidify our formulas.
some vocab words to get us started...
Triangle- shape with three sides
Parallelogram- shape with four sides in which
opposite sides are parallel from each other.
base (b)- the bottom
height (h)- distance from bottom to highest point
Formula for area of a triangle:
A=
1
b∗h
2
examples of using it...
Formula for area of a quadrilateral:
A= b∗h
examples of using it...
7in
1)
16in
2) base of 24mm and height of 13mm
1)
9 ft
42 mm
4 ft
HW: w.s...
triangle side do problems 1, 4, 9, 17
quadrilateral side do problems 4 - 7
math 7
21 mm
2)