area & perimeter of triangles. the formula for a triangle can be determined from using...
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Area & Perimeter of Triangles
The formula for a triangle can be determined from using parallelograms. Cut a parallelogram in half it forms 2 triangles.
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Therefore, a triangle’s area is ½ of the area of a parallelogram.
Not in notes
h
b
A = 12
bhThe area A of a triangleis half the product of itsbase b and its height h.
The perimeter of a triangle -add the three sides that form the triangle.
h1
2
3
Find the area of the triangle.
5
8
A = 12
bh Use the formula.
A = 12
(8 · 5) Substitute 8 for b and 5 for h.
A = (40)
EX1)
9
A = 12
bh
A = 12
(9 · 12)
A = 54
12
EX2)
12
A = 20
A = 12
(108)
notes
Area & Perimeter of Triangles
Date _____________
The area A of a triangle
The perimeter of a triangle -h
Find the area of the triangle.EX1)
EX2)