PLZ HELP ME

The graph models this system of inequalities.

y ≥
1
2
x + 1
y ≤ −4x + 3

What color represents the area that ONLY contains the solutions for y ≥
1
2
x + 1?
A) red
B) white
C) purple
D) blue

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?