A cone with a bottom radius of 20cm and a height of 27cm and a cylindrical aluminum block with a bottom radius of 30cm and a height of 20cm are fused into a cylindrical aluminum block with a bottom radius of 15cm. What is the height of the cylinder?

The total volume is 3.14 × 20 × 20 × 27 × 1 / 3 + 3.14 × 30 × 30 × 20 = 67824 cubic centimeters
The bottom area is 3.14 × 15 × 15 = 706.5 square centimeter
So the height is 67824 △ 706.5 = 96cm

Find the area of triangle
Given the triangle ABC, B'2 + C'2-a'2 = 1, C = 60 degrees, find the triangle area. I think this problem is not sufficient

Under the agreement of all kinds of great gods and mathematical talents I know, the conditions are insufficient! I can't do it

There is a real basis for the science essay of grade three in primary school

The value of a big tree is a broad-leaved tree that has grown normally for 50 years. Its branches and leaves can cover about half an acre of land. In these 50 years, how much is its ecological function and economic value? According to the calculation of scientists, this big tree exhales 44.5 kg of oxygen every day, which is enough for 32 people to breathe

In the triangle ABC, ab = AC, BAC = 90 degrees, point D is the point on the ray BC, connecting ad, taking ad as one side and on the right side of AD, making a square ADEF,

Is the question incomplete

As shown in the figure, in isosceles RT △ ABC, point D is any point on BC, connecting ad, crossing point B as be perpendicular to ad, intersecting ray ad at point E, connecting CE, and calculating the degree of ∠ AEC

When ∫ C = 90 °, be ⊥ ad, ∪ ACD = ∨ DEB, and ∨ ADC = ∨ BDE, ∨ ACD ∨ bed, ∨ DECD = bdad, there is debd = CDAD, and ∨ CDE = ∨ ADB, ∨ AEC = ∨ abd, ∨ isosceles RT △ ABC, ∨ C = 90 ° and ∨ AEC = ∨ abd = 45 °

In the triangle ABC, point D is the midpoint of BC, which is used as ray ad. in the extension line of line ad, point E.F is taken respectively to connect CE.BF Add a condition such that BDF ~ = CDE and prove it

ED=FD,
Proof: it can be seen from the drawing that ∠ CDE = ∠ FDB
Because D is the midpoint of BC
So DC = BC
And because ed = FD
So △ BDF ≌ △ CDE (edge)

It is known that in △ ABC, ∠ ACB is an acute angle and D is a moving point on the ray BC (D and C do not coincide). Take ad as one side and make equilateral △ ade to the right side (C and e do not coincide) to connect CE
(1) If △ ABC is an equilateral triangle, when point D is on line BC (as shown in Figure 1), then the acute angle between line BD and line CE is______ (2) if △ ABC is an equilateral triangle, when point D is on the extension of line BC (as shown in Figure 2), is the conclusion you got in (1) still true? (3) if △ ABC is not an equilateral triangle, and BC > AC (as shown in Figure 3), try to explore whether the conclusion you got in (1) is still true when point D is on line BC? If it is true, please explain the reason; if not, please point out when ∠ ACB meets what conditions, can make the conclusion in (1) true? And explain the reason

(1) If △ ABC is an equilateral triangle, when the point D is on the line BC, △ ABC is an equilateral triangle, equilateral △ ade, ｜ AB = AC, AE = ad, ∵ ∠ bad = 60 °～ DAC, ∵ CAE = 60 °～ DAC, ≌ bad = ∠ CAE, ≌ abd ≌ ACE (SAS), ≌ B = ∠ ace = 60 °, ECF = 180 °～ acb-60 ° = 60 °, and the acute angle between the straight line BD and the straight line CE is 60 °; & nbsp; (2) There are still lines BD and CE whose acute angle is 60 degrees. It is proved that ∵ ABC and △ ade are equilateral triangles, ∵ AB = AC, ad = AE, ∵ BAC = ≌ DAE = 60 degree, ∵ BAC + ≌ CAD = ≌ DAE + ∩ CAD, that is,

A cone with a bottom radius of 20cm and a height of 27cm and a cylindrical aluminum block with a bottom radius of 30cm and a height of 20cm are fused into a cylindrical aluminum block with a bottom radius of 15cm. What is the height of the cylinder?