How do you calculate the cross-sectional area of a pipe?
Cross section area of a cylinder ( in this case pipe) = pie*r^2 where r is the radius of the pipe.To get the radius divide diameter of the pipe by 2Let diameter = dThen r = d/2Cross sectional area = pie (d/2)^2= 3.14(d^2/4)
Find the area of the shaded region in the figure. Round to the nearest unit. Use pie=3.14?
assuming the figure to be a parallelogram with a circle of radius 2 mm inscribed... the sides of the IIgram are 12 and 6 mm resp. A = area of a IIgram = bxh (base x height) let the base be the 12 mm side, thus h = 2xr = 4 mm A = 12x4 = 48 mm² area of circle = pi x r² = 3.14 x 2² = 4 x 3.14 = 12.56 mm² thus area of shaded portion = A - area of circle => = 48 - 12.56 = 35.44 mm² Ans = 35.44 mm² ~= 35 mm²
If the question says two decimal places, does it mean I have to just stop at two decimal places or do I have to do 3 decimal places, followed by the third decimal place?
Assuming that I have understood you correctly (I have found the last part of the question a little fuzzy...)If the question asks for 2 d.p., you first go to 3 d.p.:3.141592654 -> 3.141Then you round the number to 2 d.p. according to what the number is at the 3rd d.p.:If it is <= 3.144 then 3.14If it is >=3.145 then 3.15
What is the answer if square is inscribed in the circle then the ratio of there area will give what?
Let side of square be 'a'Area of square is a²Diagonal of sqare is √{a²+a²}Or √2aSo diameter of circle is equal to diagonal of sqare.Then diameter=√2aRadius(r)=√2a/2=a/√2Area of circle=πr²=π{a/√2}²=πa²/2Ratio of area of square and area of circle =a²:πa²/2=1:π/2=2:π
What if the circumference of a circle is 44 cm, then what is its area?
If r is the radius of given circle, thenCircumference 2πr=44cmPutting π=22/72×(22/7)r=44r=44×7/(22×2)r=7cmNow area=πr^2=(22/7)×7×7=22×7=154sq.cm
How do you find the perimeter of a quarter circle?
If the radius is given, compute the perimeter of the whole circle, it is given by the formula [math]C=2 \pi r[/math] where: C=circumference or perimeter of the circle and r=radius of the circle. After that, divide the result by 4. Remember a circle is made up of 4 quarter circles. The result after dividing by 4 is the length of the arc. To get the perimeter, add the length of the two radius (right figure).
An equilateral triangle is inscribed in a circle. If the radius of the circle is 2, what is the area of the triangle?
This is one of those cases where it helps to draw a diagram.Draw an equilateral triangleDraw perpendicular lines from each corner of the triangle to the opposite sideDraw a circle that circumscribes that triangle.Here are some things to observe:The center of the triangle is at the same place as the center of the circleThe height of the triangle is equal tothe radius of the circle (distance from corner to the center), plushalf the radius of the circle (distance from center to triangle’s base).This height (150% of the radius) agrees with what we know about triangles (the center is two thirds of the way from any corner to the center of the opposite side).If the center of the circle (and triangle) is at (0,0), then the top of the triangle is at (0,2) and the height of the triangle intersects the base at (0,-1). Label these points.Now, we need to calculate the width of the triangle. Let’s label the width of the triangle with the letter w (yes, clever of me, isn’t it?) and the height with the value 3, which unfortunately looks like a w on its side, but it is a 3.Do you see that we have a right triangle that is w/2 units wide, 3 units tall, with a hypotenuse of w units?Let’s use the Pythagorean Theorem to calculate the value of w:a² + b² = c²[math](\frac{w}{2})² + 3² = w²[/math][math]\frac{w²}{4} + 9 = w²[/math]Let’s subtract w²/4 from both sides of the equation:[math]\frac{w²}{4} - \frac{w²}{4} + 9 = w² - \frac{w²}{4}[/math][math]9 = \frac{3w²}{4}[/math]Multiply both sides of the equation by 4/3:[math]\frac43∙9 = \frac43∙\frac{3w²}{4}[/math][math]12 = w²[/math]So, we now see that w is equal to 2√3, which means that w/2 is equal to √3.Let’s double-check our math.a² + b² = c²(√3)² + (3)² = (2√3)²3 + 9 = 12 → yes, that checks out.Let’s put that back into our original diagram:So, what is the area of this triangle? Multiply the height times the width, then divide by 2. I’ll let you finish from here.[math]A = \frac{hw}{2}[/math]
How do I calculate the radius of a circle with the length of a chord = 40 and the perpendicular distance from the midpoint of the chord to the perimeter of the circle = 14?
First we have the length the chord =40Now the radius is assumes to be equal to r So the perpendicular distance from the centre to the chord is = (r-14) After getting two distances we now have a right triangle with hypotenuse equal to r and one side equal to (r-14) The third side is given by the half of the chord =20Solve the hypotenuse equation given by r^2 = (r-14)^2 + 20^2 Solve for the value of r The radius value comes to ~ 21.287