a solid pyramid with a square base with side 12 cm and height 25 cm is made of metal. The metal is melted to form spherical ball bearings of radius 7 mm. How many pyramids are needed to form 2490 ball bearings?

3 pyramids.

Step-by-step explanation:

The volume of one pyramid is 1/3 * b^2 * h

= 1/3 * 12^2 * 25

= 1200 cm^3.

The volume of one ball bearing = 4/3 * π * 0.7^3

= 1.43676 cm^3.

Therefore the volume of 2490 ball bearings = 2490 * 1 .43676

= 3577.53 cm^3.

So we need 3577.53 / 1200 = 2.98 = 3 pyramids.

step-by-step explanation:

the multiplicative inverse of a fraction a/b is b/a. for the multiplicative inverse of a real number, divide 1 by the number. for example, the reciprocal of 5 is one fifth 1/5 or 0.2, and the reciprocal of 0.25 is 1 divided by 0.25, or 4.

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it