"The sum of twice a number and 10 is 36"

13

Step-by-step explanation:

X*2+10=36

x*2=26

x=13

hi friend

here is your answer

there are two angles that are alternate interior angle with angle 9

the angle 15 and angle 7 are alternate interior angle with angle 9.

hope it is for you so mark my answer as a brainliest

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.