Answer:
Since it is an equilateral triangle, all sides are 10cm
Step-by-step explanation:
Don't be shy about using actual parentheses and commas.
Line through (1,8) perpendicular to

The perpendicular family is gotten by swapping the coefficients on x and y, negating exactly one of them. The constant is given directly by the point we're through:

Let's clear the fractions by multiplying both sides by 20.

Might as well stop here.
Answer: 25 x + 16 y = 153