Look at the figure. Which reason justifies that _PRS and PRT are right angles?

the mistake in the pattern is that :

b. the decimal point was moved one too many place values each time

the correct pattern could be made by :

b. moving the decimal point to the right the same numbers of place values as the exponents

well it says right there your brother is 13; "your age". so lets keep it simple. you are 13 years old and there is no way to put this into any kind of equation without wanting to tear your hair out. who came up with this?