Gina has 20 groups of 10 pencils 137 are sharpened how many dual pencils does gina have

well, I think the whole group thing is ment to distract you. Math problems can be evil like that. If she has 200 pencils. and 137 ove them a sharp, you have to subtract 137 from 200.      200-137=23 :3 she has 23 unshapened pencils.

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.