Transcript 10-1: Area of Parallelograms and Triangles

10-1: Area of Parallelograms
and Triangles
Learning Goal: Calculate the area of
parallelograms, triangles, and composite
figures made from parallelograms and
triangles
Area of a Parallelogram
 What is the formula for area of a
rectangle?
 The area of any rectangle can be made
into a generic parallelogram, so the
formula is the same!
 Area of a parallelogram = base(height)
 A = bh
 Formula is on the EOC reference sheet
Corresponding base and heights
 There are 2 bases and 2 altitudes
(heights) to every parallelogram,
depending on which way you turn it
 Corresponding base and height will be
perpendicular to each other!
EX 1: Calculate the area
EX 2: Finding Missing dimensions
EX: Finding missing dimensions
 A parallelogram has sides 15cm and
18cm. The height corresponding to a
15cm base is 9cm. What is the height
corresponding to the 18cm base?
Area of a triangle
 Area of a triangle = ½ (base)(height)
 A = ½ bh
 Must be corresponding base and height!
 Formula on EOC reference sheet
 EX 4: What’s the area of the triangle?
Composite Shapes
 What is a composite shape?
 Composite shape – a figure made from
common shapes such as triangles,
parallelograms, or circles
 EX 5: Calculate the area
of the figure.
Assignment
 You will receive your chapter 10 progress
trackers next week.
 Heading:
10-1 pg 637 #8, 9, 11, 12, 15-19, 27
Due Thursday for periods 1 & 5
Due Friday for periods 2 & 7
10-1 Answers…questions?
2
16)
a.
1390
ft
8) 26.79
b. Awhole - Aflowers
2
9) 20.3 m
c. 1390 ft2
11) 0.24 units
17) 88cm2
8
12)16 units or
18) 4in
13
approx 16.62 units 19) 14cm
2
27)
12,800
m
15) 3 ft2
in2