BRAINLIESTT ASAP! PLEASE HELP ME ASAP! :)

Here's what I did  

Step-by-step explanation:

Use the identity  

sin²x + cos²x = 1, Then

sin²x =  1 - cos²x, and

sin²x - 1 = -cos²x and

cos²x - 1 = -sin²x

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.

search the worksheet up on the internet

step-by-step explanation:

it works trust me