Pls help and zoom in if u can’t see it

Hi, I would love to help you, but I can not see the rest of the question- even after zooming in!

Pls upload/ tell the full picture.

Thank you!

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

the expression (1.26)2t reveals the approximate rate of increases in the number of plants semiannually.

hope this : )