In △ ABC, the edge BC = 16, the height ad on the edge BC = 8, the quadrilateral efgh is the inscribed rectangle of the triangle, and EF = 2fg, find the s rectangle efgh RT, RT It's the whole process

In △ ABC, the edge BC = 16, the height ad on the edge BC = 8, the quadrilateral efgh is the inscribed rectangle of the triangle, and EF = 2fg, find the s rectangle efgh RT, RT It's the whole process

In triangles ABC and AGH, a is the common angle AGH = ACB ABC = AHG
So triangle ABC and AGH are similar
Let the width of the rectangle be h and the length be 2h, then: (AD-H) / ad = 2H / BC (the corresponding sides of similar triangles are proportional)
(8-h) / 8 = 2H / 16, H = 4
S=h*2h=4*8=32

Is there a watch on the desk

are there some watches on the desk

In △ ABC, cosa = 3 / 5, SINB = 5 / 13, find sinc=

∵0

Can the little boy___ (wirte) his name?
Fill in the blanks with the proper form of the words given

Write, can in front is a modal verb, followed by the original form

A cylindrical flower bed is to be built next to the school playground. The inner diameter of the bottom of the flower bed is 4 meters and the height is 0.6 meters. If the height of the filling is 0.4 meters, how many cubic meters of filling is needed to build the flower bed?

3.14 × (4 △ 2) 2 × 0.4 = 3.14 × 4 × 0.4 = 5.024 (cubic meter) a: the construction of this flower bed needs 5.024 cubic meters of filling

The opposite of "worse" is "wet"

good
dry

The typhoon code named "storm" formed at 8:00 p.m. on the sea surface of 400 km, 60 ° south by east from wharf a of the port. It is estimated that the typhoon center will move due north at the speed of 40 km / h, and the area 350 km away from the typhoon center will be affected by the typhoon. How many hours will wharf a last from being affected by the typhoon to the end of the impact______ ．

If the typhoon center is regarded as point B at the sea surface of 400 km to the south by east of wharf a, then AB = 400 passes through B and BC is perpendicular to the east line at point C, then BC = 200, AC = 2003. The range of 350 km from the typhoon center will be affected by typhoon. Therefore, taking point D on BC line makes ad = 350 km, because AC = 200 km, ad = 350 km ∠ DCA is right angle. According to Pythagorean theorem, DC = 3502 − (2003) 2 = 50 km Because 350 km will be affected by typhoon, so the influence distance is 50 × 2 = 100 km, t = 100, 400 = 2.5 (hours), so the answer is 2.5 hours

The past continuous tense the present continuous tense
It's a special usage
Help to be more specific

What is the principle of keyhole imaging?

A: pinhole imaging is formed by the linear propagation of light

Are inductors and capacitors opposite?

It's reasonable, but it can't be understood in this way, for example:
1. From the perspective of series connection: inductance hinders the passage of high frequency, while capacitance allows the passage of high frequency, which is consistent with what you said;
2. From the point of view of energy storage: inductance blocks current and stores current as electric energy, capacitor stores voltage and stores voltage as energy;
3. From the perspective of phase, the current in the inductor lags behind the voltage, and the current in the capacitor precedes the voltage;
-------There are many more, so it can not be simply understood as "the opposite"