The bottom radius of a cylinder is 4 decimeters, and its height is 50% shorter than the radius. Its surface area is () square decimeters, which is the same as the volume of a cone with equal bottom and equal height () cubic decimeter

The bottom radius of a cylinder is 4 decimeters, and its height is 50% shorter than the radius. Its surface area is () square decimeters, which is the same as the volume of a cone with equal bottom and equal height () cubic decimeter

High: 4 × (1-50%) = 2 (DM)
S column: 4 × 2 × 3.14 × 2 + 4 × 4 × 3.14 × 2
=50.24+100.48
=150.72（dm²）
V-cone: 4 × 4 × 3.14 × 2 × (1 / 3) (one third)
=33.49333… (3 cycles)
≈33.49（dm³）
These are all typed by myself. I helped others to the end

A trapezoid, the area is 63 square decimeters, the height is 3 meters, the bottom is 18 meters
What is the top and bottom of this trapezoid

It doesn't exist!
Topic: a trapezoid, the area is 63 square meters, the height is 3 meters, the bottom is 18 meters
Upper bottom = area * 2 / height - lower bottom = 63 * 2 / 3-18 = 24

The radius of the bottom of the cylinder is 2cm, the surface area is () square centimeter, and the volume is () cubic centimeter（
）Cubic centimeter

The surface area is 40 π square centimeters
The volume is 40 PI square centimeters
The volume of a cone of equal base height is 40 / 3 π square centimeter

How many diagonals of a parallelogram and triangles of equal area can it form

Four
If the parallelogram is ABCD, the four triangles are ABC = triangle DBC = triangle CAD = triangle bad

The volume and height of a cylinder and a cone are equal respectively. The perimeter of the known ground area is 12.56cm, so the ground area of the cone can be calculated!
It's no use tomorrow!

Volume calculation formula of cylinder: v = π * r * r * h
The volume formula of cone: v = 1 / 3 * π * r * r * h
The volume and height of a cylinder and a cone are equal,
So the bottom area of a cone is three times that of a cylinder,
The circumference of the bottom of the cylinder is 12.56cm
So the bottom area of the cylinder is 12.56 cm ^ 3
So the bottom area of the cone is 37.68cm ^ 3
I hope my answer will help you

The height of a triangle is three times that of its base. How many times is the area of the quadrilateral formed by two such triangles?

2 times. Sweat

Parallelogram two diagonals divide parallelogram into four triangles of equal area, right or wrong? If right, how to prove?

Yes. Because two triangles are congruent, so are their areas

The proposition "the distance from any point on the middle line of the bottom edge of an isosceles triangle to the two waists is equal" is correct______ Proposition (fill in "true" and "false")

According to the property of isosceles triangle's three lines in one, it can be concluded that: the middle line on the bottom edge of isosceles triangle coincides with the bisector of vertex angle, the distance between the point on the bisector of ∵ angle and the two sides of the angle is equal, and "the distance between any point on the middle line of isosceles triangle's bottom edge and the two waists is equal" is a true proposition, so the answer is: true

It is proved that the midlines on the two waists of an isosceles triangle are equal

It is known that ab = AC, ad = DC, AE = EB in isosceles △ ABC, and BD = CE is proved. It is proved that ∵ AB = AC, ad = DC, AE = EB, ∵ DC = be, ∵ DCB = ∵ EBC. ∵ BC = CB, ≌ BDC ≌ CEB (SAS) ≌ BD = CE. That is to say, the midlines on the two waists of isosceles triangle are equal

It is proved that the heights of the two waists of an isosceles triangle are equal

ZM: as shown in the figure, in △ BDC and △ CEB, ∵ ∠ DBC = ∠ ECB, ∵ BDC = ∠ CEB = 90 °, BC = BC, ≌ BDC ≌ CEB, CD = be