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Transparency 11-2. 5-Minute Check on Lesson 11-1. Find the area and the perimeter of each parallelogram. Round to the nearest tenth if necessary. 2. 3. 4.
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Transparency 11-2 5-Minute Check on Lesson 11-1 • Find the area and the perimeter of each parallelogram. Round to the nearest tenth if necessary. • 2. • 3. 4. • TRY: Find the height and base of this parallelogram if the area is 168 square units 17 ft 11 cm 13 cm 12 ft 45° 11 in 60° 18 in 6.3 m x + 2 x Click the mouse button or press the Space Bar to display the answers.
Lesson 11-2 Day 1 Areas of Triangles
Area of Triangles R Triangle Area A = ½ * b * h h is height (altitude) b is base (┴ to h) h T S W
EXAMPLE 1 R Find the area of triangle RST h 45° S T W 10 10
Example 2-1a EXAMPLE 2 Find the area of quadrilateral ABCD if AC = 35, BF = 18, and DE = 10.
Example 2-1b EXAMPLE 3 Find the area of quadrilateral HIJK if IK = 16, HL = 5 and JM = 9
EXAMPLE 4 • Find the area of the triangle whose vertices are (3,6), (7,6) and (3,1).
EXAMPLE 5 • Find the area of the parallelogram whose vertices are (0,0), (4,0), (5,5), and (1,5)
Summary & Homework Summary: The formula for the area of a triangle can be used to find the areas of many different figures Congruent figures have equal areas Classwork:YOU MUST SHOW WORK!!!!! pg 605 (5,13, 14, 19, 20, 34, 35) pg 599 (21-25 and page 605 #7) Plot points first then find the area of each!!!