We can employ some logic to reduce the answers we need to test. We know that the slope perpendicular to line l has to have a negative reciprocal slope, so a slope of
. We see that in A and C, as x increases so does y. That means the slope of these equations are positive, which we don't want. Now for some algebra:

We se that D has the correct slope so that must be the answer.
Answer:
One forth of 20 is 5, so there are 5 kindergarten and first grade classrooms.
5 x 2 is 10 so there are 10 second and third grade classrooms.
10 + 5 is 15.
20 - 15 is 5.
There are 5 forth and fifth grade classes.
Step-by-step explanation:
Answer:
GH = 5, HI = 6, GI ≈ 7.81
m∠H = 90°, m∠G ≈ 50°, m∠I ≈ 40°
Step-by-step explanation:
Area of parallelogram
= L × H
= 23 × 13
= 299 feet²