# SECTION 11.1 AREAS of RECTANGLES and SQUARES. WARM UP 1)Find the area and perimeter of a square that is 5 inches long. 2)The area of a square is 64 cm.

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SECTION 11.1 AREAS of RECTANGLES and SQUARES

WARM UP 1)Find the area and perimeter of a square that is 5 inches long. 2)The area of a square is 64 cm 2. What is the perimeter? 3)The perimeter of a square is 28 inches. What is the area? A = 5 · 5 = 25P = 5 + 5 + 5 + 5 = 20 A = 64, 8 = side P = 8 + 8 + 8 + 8 = 32 cm P = 28, 28/4 = 7A = 7 · 7 = 49 in 2

PERIMETER TO FIND PERIMETERS Add all the side lengths together!

Area of SQUARES Area of a square = sides 2 = s 2

Area of RECTANGLES A = bh or A = lw Base x height length x width

Find the area and perimeter. NOTE: It is a rectangle. Remember you can only combine “like” radicals!

Give the expression for the area and perimeter. NOTE: It is a rectangle. A = 2x(x – 3) A = 2x 2 – 6x That is as far as you can go! P = 2(x – 3) + 2(2x) P = 2x – 6 + 4x P = 6x – 6

Find the area and perimeter. HINT: It’s a special right triangle! I love these guys! 30 0 5

SAT Problem The area of the rectangle is 60 square units. Find the value of x. a)⅔ b)7 c)8 d)40 e)59 2x - 1 ½x A = bh 60 = (2x – 1)( ½x) 60 = x 2 – ½x 0 = x 2 – ½x – 60 This is UGLY. Try to Guess and Test. x = 8

Real Life Applications

How much will it cost to blacktop the driveway shown if blacktopping costs \$11.00 per square meter? HINT: ADD A LINE!!!! HINT: You are finding area! 6 m 5 m 4 m A = 5(6) = 30 A = 4(18) = 72 TOTAL AREA = 72 + 30 = 102 m 2 TOTAL COST = 102(11) = \$1,122

Draw a picture A path 2 m wide surrounds a rectangular garden 20 m long and 12 m wide. Find the area of the PATH. 2 m 20 m 12 m A = 20(12) = 240 m 2 A = 24(16) = 384 m 2 2 m 24 m 16 m Total Area - Garden384 – 240 = 144 m 2

PRACTICE Page 426 #2 – 12 EVENS #23, 24

Area Video Don’t you just love these videos!!!!videos

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