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Topic: **Perimeter and area homework****Question:**
http://img142.imageshack.us/my.php?image=imgei9.jpg
#s 12, 16, 18, 19 and 20 please
can you also show me how to do them?
thanks

June 20, 2019 / By Erynn

12) a circle with radius r=7 pi ~ 3.14 area of a circle is pi*r^2 => pi*7^2 circumference is 2*pi*r => 2*pi*7 use the calculator for final result. 16) a circle is given with diameter D=11 i.e;. 2r=11 so r = 11/2 using the above eqs area => pi*(11/2)^2 circumference => 2*pi*(11/2) = pi*11 18) we have a paralleogram with one side and the diagonal. Using the lower right hand half as the right angle triangle, we have one side and the opposite side so to get the third side we ca nuse the traingle law of side1^2 + side2^2 = oppisite side^2 6^2 + side2^2 = 10^2 36 + side2^2 = 100 side2^2 = 100 - 36 = 64 side2 = 64^(1/2) <= sqrt of 64 = 8 side2 = 8 now area is side1 * side2 or length * breadth = 6 * 8 perimeter is 2*(side 1 + side2) or 2*(length + breadth) = 2*(6 + 8) = 2*(14) 19) we have a right angle traingle with one side and the opposite side. using the equation for traingles we get side1^2 + side2^2 = opposite side^2 5^2 + side2^2 = (5*2^(1/2))^2 = (5^2)*(2^((1/2)*2)) = (5^2)*2 side2^2 = 2*(5^2) - (5^2) = (5^2) side2 = (5^2)^(1/2) = 5 side2 = 5 area for traingle is (1/2)*(base)*(height) => (1/2)*(side1)*(side2) = (1/2)*5*5 20) is a semi circle with radius of 8 using eq for area of a circle and divide it by 2 so it is (pi*r^2)/2 = (pi*8^2)/2 circumference is half the circumference of the circle + diameter so (2*pi*r)/2 + 2*r = pi*r + 2*r = pi*8 + 2*8 = (pi + 2)*8

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Did you like the answer? We found more questions related to the topic: **Perimeter and area homework**

1) 33m/hr * 1000cm/m = 33000cm/hr 2) 16 lbs/ft * 16 oz/lb = 256 oz/ft 3) 4.5 L/min * 1000 mL/L * 1min/60sec = 75 mL/sec 4) 3 mi/hr * 5280 ft/mi * 24 hr/day = 380160 ft/day

1 METER = 100 CM 33 METERS = 3300 CM ANSWER 2) 1 lb = 16 oz 16 lb = 16x 16 = 256 oz per foot answer 3) 1 L = 1000 ML 4.5 L = 4500 ML 1 MINUTE = 60 SECONDS = 4500 ML 1 SECOND = 4500/60 = 75 ML PER SECOND ANSWER 4) 1 DAY = 24 HOURS 1 HOUR = 3 MILES 24 HOURS = 72 MILES 1 MILE = 5280 FEET 72 MILES = 72 X 5280 FEET. PLEASE CALCULATE.

12 Circle - Given r = 7 A = π r² A = 3.14 (7²) A = 3.14 * 49 A = 153.86 C = 2π r C = 2 * 3.14 * 7 C = 6.25 * 7 C = 6.25 #16 Circle - Given d = 11 r = d / 2 r = 11 / 2 A = π r² A = 3.14 * (11/2)² A = 3.14 * 121/4 A = 3.14 * 30.25 A = 94.985 C = 2π r C = 2 * 3.14 * (11/2) C = 3.14 * 11 C = 34.54 #18 Rectangle - Given diagonal = 10 and h = 6 Find the length of the other side using the Pythagorean Theorem. a² + b² = c² where a and b are the sides of your right triangle and c is the hypotenuese. 6² + b² = 10² 36 + b² = 100 b² = 64 b = 8 You now have length (L) = 8 and height or width (W) = 6. A = L × W A = 8 × 6 A = 48 P = 2L + 2W = 2(L + W) P = 2(8 + 6) P = 2(14) P = 28 #19 Right triangle - Given height = 5 and hypotenuese = 5√2. Use Pythagorean Theorem to get the other side. 5² + b² = (5√2)² 25 + b² = 25*4 25 + b² = 100 b² = 75 b = √75 = √(25*3) = 5√3 A = 1/2 × b × h A = 1/2 * 5√3 * 5 A = 1/2 * 25√3 A = (25√3)/2 P = Sum of the three sides P = 5√3 + 5√2 + 5 P = 5(√3 + √2 + 1) #20 Half Circle - Given r = 8 (Since the 8 is on one side of the center, I'm am calculating it as the radius, not the diameter.) Area of a full circle is π r² so the area of a half circle would be that divided by 2. A = (π r²)/2 A = (3.14 * 8²) / 2 A = (3.14 * 64) / 2 A = 200.96 / 2 A = 100.48 Same goes for circumference. C = 2π r, so for a half circle, divide by 2. C = (2π r) / 2 or π r C = π r C = 3.14 * 8 C = 25.12

👍 100 | 👎 3

I agree with all of ajordan971's answers except for the one for #19. She correctly uses the Pythagorean Theorem to find the third side. a^2 + b^2 = c^2 5^2 + b^2 = (5√2)^2 Here's where I think she made a mistake. Isn’t the square of (5√2) fifty instead of one hundred? Let’s write it out: 5 * 5 * √2 * √2 5 * 5 = 25 √2 * √2 = 2 25 * 2 = 50 25 + b^2 = 50 b^2 = 25 b = 5 Perimeter = 5 + 5 + 5√2 P = 10 + 5√2 Area = ½ * height * width A = ½ * 5 * 5 A = 12.5 sq

👍 95 | 👎 0

C(x) = 0.43x2 +18.3x +15.6 R(x) =xp =x{-0.02x+129 = -0.02x^2 +129x R(x) - C(x) >0 -0.02x^2 +129 x - 0.43 x^2 -18.3x -15.6 >0 -0.45 x^2 +110.7x -15.6> 0 0.45 x^2 -110.7 x +15.6 < 0 x < 110.7 +/- {sqrt (110.7)^2 - 4*(0.45)(15.6)}}/0.9 x < [110.7 + 110.5698421813109/0.9 < 245.8553802014565555556 x < 245 jackets....................................

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