The elements that are visible include A, B, and C.
Answer:

Step-by-step explanation:
Given:
KL ║ NM,
LM = 45
m∠M = 50°
KN ⊥ NM
NL ⊥ LM
To determine: KN and KL
1. Analyzing triangle NLM, we see it is a right triangle due to NL ⊥ LM. In this context,
LM = 45
m∠M = 50°
Consequently,

It is also true that
(angles LNM and M are complementary).
2. Now considering triangle NKL, it also forms a right triangle as KN ⊥ NM. Within this triangle,
(alternate interior angles)
(angles KNL and KLN are complementary).
Thus,

and

This situation exemplifies the distributive property, where the number outside the parentheses impacts all the terms within through multiplication. Therefore, the resulting action here is:
<span>The 4 should be multiplied by each term found inside the parentheses.
</span>
Here’s a counterexample: consider

Select the subsets in the following manner:

It's accurate that
and
and that
, but 
Since this parabola intersects the center, its formula is:
y = ax². Given that it opens downward, the coefficient a must be negative.
Thus, the equation can be expressed as:
y = - ax², with the axis of symmetry located at x = 0.
The height measures 84 ft when the parabola's opening is 42 ft wide.
This indicates that for the height y, the corresponding x-values are +21 and -21 (due to symmetry).
To find a, let's substitute y and x with their respective values:
y = - ax²
84 = - a(21)²
84 = - a(441), leading to a = - 84/441 ↔ a = - 4/21.
Therefore, the final equation is: y = -4/21 x².