Answer:
C 180-123
Step-by-step explanation:
This is because 180 is what triangles always equal and if one angle is 128 then the rest will be answered from this equation
The 2x and 76 are opposite angles so they are equal.
2x = 76
x = 38 degrees
y and 76 are adjacent angles so y = 180 - 76
= 104 degrees
Answer:

Step-by-step explanation:

The equation that can be used to determine the dimensions of the base of the doghouse is x² + 4x = 21
<h3>
What is the equation?</h3>
A quadratic equation is an equation that usually has a single variable and it is raised to the power of 2.
Area of a rectangle = length x width
x (4 + x) = 21
x² + 4x = 21
To learn more about quadratic equations , please check: brainly.com/question/27696091
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