RT,在三角形abc中,AB=AC=10,点D在BC上,DE平行AC,DF平行AB,求四边形AEDF的周长.

RT,在三角形abc中,AB=AC=10,点D在BC上,DE平行AC,DF平行AB,求四边形AEDF的周长.
RT,在三角形abc中,AB=AC=10,点D在BC上,DE平行AC,DF平行AB,求四边形AEDF的周长.

RT,在三角形abc中,AB=AC=10,点D在BC上,DE平行AC,DF平行AB,求四边形AEDF的周长.
周长就是AB+AC=20
因为AB=AC,所以∠B=∠C,又因为DE平行AC,DF平行AB,那么就有∠B=∠EDB,∠C=∠FDC,则EB=ED,FC=FD,四边形周长等于AE+AF+DE+DF=AE+BE+AF+FC=AB+AC=20

notebook cooling pad CPU fan blades are usually between 6-12.
In general, leaves a smaller number of easy to have a greater pressure, but also a larger operation noise; and a large number of lea...

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notebook cooling pad CPU fan blades are usually between 6-12.
In general, leaves a smaller number of easy to have a greater pressure, but also a larger operation noise; and a large number of leaves is just the opposite.
The direction of the wind
Divided into two kinds of axial and centrifugal.
As the name suggests, axial flow of the wind direction is the direction along the fan axis, ie perpendicular to the blade rotation direction of the surface wind; centrifugal type of the wind direction is the path along the blade surface rotation in all directions out of longing for the wind. Basically, the current CPU cooler are used axial fans, centrifugal fans used only Coolermaster's "Tornado" series. From the practical effect of view, centrifugal fans are not working full advantage of the wind out, but the work will increase noise, so not a good option. However, the radiator fan with centrifugal thin shape is easier to do, so often a number of cards to be used in the cooling system.
The speed of rotation notebook cooling pad
Can be divided into two types Powerful and silent type.
This classification is not too strict, but the same size, same type of fan, the wind pressure and noise will always be unable to reconcile the two conflicts.
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Technical Specifications
Fan power
notebook cooling pad
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