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Area of Parallelograms. Re-cap. What is the formula for area of rectangle? What is the formula for the surface are of a rectangle? What is the formula for the volume of a rectangular prism?. Goal. Find the area of parallelograms. Key Vocabulary. Base of a parallelogram
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Re-cap... • What is the formula for area of rectangle? • What is the formula for the surface are of a rectangle? • What is the formula for the volume of a rectangular prism?
Goal • Find the area of parallelograms.
Key Vocabulary • Base of a parallelogram • Height of a parallelogram • Parallelogram • Rhombus
Parallelogram • A parallelogram is a quadrilateral where the opposite sides are congruent and parallel. • A rectangle is a type of parallelogram, but we often see parallelograms that are not rectangles (parallelograms without right angles).
The Base of a Parallelogram • Either pair of parallel sides of a parallelogram are called the bases of the parallelogram. base base base base
The Height of a Parallelogram • The shortest distance (perpendicular distance) between the bases of a parallelogram is called the height of the parallelogram. • The height of the parallelogram is always perpendicular to the bases.
Area of Parallelogram What is the area of this parallelogram? h=height b=base
Area of Parallelogram What is the area of this parallelogram? h=height b=base CUT HERE!
Area of Parallelogram What is the area of this parallelogram? h=height b=base MOVE TO HERE!
Area of Parallelogram It’s the same as the area of this rectangle h=height b=base
Area of Parallelogram Arearectangle= base x height (perpendicular height h) h=height b=base
Area of Parallelogram • Words: Area =(base)(height) • Symbols: A = bh h b Very Important: The height must be perpendicular to the base.
Area of Parallelogram Areaparallelogram = base x height (perpendicular height h) h=height b=base
Find the area of the rhombus. b. a. 1 1 1 1 1 2 2 2 2 2 Example 3 Find the Area of a Rhombus SOLUTION SOLUTION a. b. A=d1d2 A=d1d2 = (6 + 6)(9 + 9) = (14)(10) = 70 = (12)(18) =108 The area of the rhombus is 70 square inches. The area of the rhombus is 108 square inches.
Practice… • Words: Area =(base)(height) • Symbols: A = bh 9.2 cm 12.5cm Very Important: The height must be perpendicular to the base.
A =bh Formula for the area of a parallelogram 78=12h Substitute 78 for A and 12 for b. 6.5 =h Divide each side by 12. The parallelogram has a height of 6.5 feet. ANSWER Example 2 Find the Height of a Parallelogram Find the height of the parallelogram given that its area is 78 square feet. SOLUTION
Practice...Find the height Area= 16m2 4cm
Practice... Area= 60cm ? cm 12cm
Wrap up... • What’s the formula for area of a parallelogram? • How would you find the height of a parallelogram when given the area and base?