What is the measurement of ∠BAC and ∠ABC? Explain your process of solving.

<BAC = 78

<ABC = 68

Step-by-step explanation:

The remote angles theorem states that when one extends a side of a triangle, the angle formed between the extension and one of the sides of the triangle is equal to the sum of the two non-adjacent angles inside the triangle. One can apply this theorem here and state the following,

<BAC + <ABC = <ACD

Substitute,

(5y + 3) + (4y + 8) = (146)

Simplify,

9y + 11 = 146

Inverse operations,

9y + 11 = 146

     -11     -11

9y = 135

/9      /9

y = 15

Now substitute this value back into the expressions to find the numerical measurement of (<BAC) and (<ABC),

<BAC = 5y + 3

5(15) + 3

78

<ABC = 4y + 8

4(15) + 8

68

step-by-step explanation:

we have

using a graphing tool

see the attached figure

this is a quadratic equation (vertical parabola) open up

the vertex is a > vertex

the domain of the function is all real > interval (-∞,∞)

the range of the function is the > [-6.125,∞)

the function has two x->   and

the function is increasing over the > (0.25,∞)

the function is decreasing over the > (-∞,0.25)