
Cross multiply:

Divide by h on both sides:
Well the volume of a cube is lbh that is length×breath×height which is given to be equal to 672.5cm3 thus lbh=672.5cm3
lb×10cm=672.5cm3 (putting value of h) solve and u obtain the Base area! (lb)
Step-by-step explanation:
Ok, imagine I have a finger pointed up, and you have your's as well. They are not congruent / parallell to each other because they are not in the same plane.
Plane: A plane is kind of the space around you, so take a paper and draw a line, the space around the line is called a plane. To make two lines parallell, they have to be straight and be in the same plane
Congruence/congruent= Equal(led) to
Postulates means that you know it without proof, for example, a right angle is 90 degrees.
There are different congruence postulates. It can be used for triangles or for other shapes.
I hope this answers your question, I am not to sure on what you said !
Proof by induction
Base case:
n=1: 1*2*3=6 is obviously divisible by six.
Assumption: For every n>1 n(n+1)(n+2) is divisible by 6.
For n+1:
(n+1)(n+2)(n+3)=
(n(n+1)(n+2)+3(n+1)(n+2))
We have assumed that n(n+1)(n+2) is divisble by 6.
We now only need to prove that 3(n+1)(n+2) is divisible by 6.
If 3(n+1)(n+2) is divisible by 6, then (n+1)(n+2) must be divisible by 2.
The "cool" part about this proof.
Since n is a natural number greater than 1 we can say the following:
If n is an odd number, then n+1 is even, then n+1 is divisible by 2 thus (n+1)(n+2) is divisible by 2,so we have proved what we wanted.
If n is an even number" then n+2 is even, then n+1 is divisible by 2 thus (n+1)(n+2) is divisible by 2,so we have proved what we wanted.
Therefore by using the method of mathematical induction we proved that for every natural number n, n(n+1)(n+2) is divisible by 6. QED.