Transcript 10.1 Areas of Parallelograms and Triangles • Area of a Rectangle – The area of a rectangle is the product of its.

10.1 Areas of Parallelograms and Triangles
• Area of a Rectangle
– The area of a rectangle is the product of its base and
height.
– A = bh
Area of a Parallelogram
• The area of a parallelogram is the product of a base
and the corresponding height.
• A = bh
Parallelograms
• A base of a parallelogram can be any one of its
sides.
• The corresponding altitude is a segment
perpendicular to the line containing that base,
drawn from the side opposite the base.
• The height is the length of an altitude.
Finding the Area of a Parallelogram
• What is the area of each parallelogram?
A  bh
A  5(4)
A  20in.
2
A  bh
A  2(3.5)
A  7cm.
2
Finding a Missing Dimension
• For parallelogram ABCD, what is DE to the nearest
tenth?
A  bh
A  13(9)  117
117  9.4( DE )
117
DE 
9.4
DE  12.4in.
Area of a Triangle
• The area of a triangle is half the product of a
base and the corresponding height.
1
A  bh
2
Finding the Area of an Irregular Figure
• What is the area of the figure?
1
A  bh
2
1
A  (6)(8)
2
A  24in.
2
A  bh
A  (6)(6)
2
A  36in. A  24in.2  36in.2  60in.2
More Practice!!!!!
• Homework – Textbook p. 619 – 620 #8 – 16,
18 – 20 ALL.