U can do tallies.. Its like little lines..That add up to 30.
Answer:

Step-by-step explanation:
Consider an equation: 
Here, m is the slope of the line and c is the y-intercept.
Given equation is 
Here, slope is 
As product of slopes of two perpendicular lines is equal to
, slope of the required line is
.
Let 
Equation of the required line is 

1:equilateral
2:isosceles
3:scalene
4:right
5:acute
6:obtuse
Step-by-step explanation:
could not find the formula ?
the volume of a cylinder is ground area × height.
and the ground area is a circle.
so, all in all we get
pi×r²×h
with r being the radius (half of the diameter), and h being the height.
in our case we get
pi×(140/2)²×10 = pi×70²×10 = 49000×pi =
= 153,938.04... cm³