Respuesta :
Answer:
∠ B = 15°
Step-by-step explanation:
Complementary angles sum to 90° , that is
∠ A + ∠ B = 90 , substitute values
8x + 27 + 6x - 21 = 90
14x + 6 = 90 ( subtract 6 from both sides )
14x = 84 ( divide both sides by 14 )
x = 6
Thus
∠ B = 6x - 21 = 6(6) - 21 = 36 - 21 = 15°
Answer:
16
Step-by-step explanation:
(3x+9)+(6x+27)=
(3x+9)+(6x+27)=
\,\,180
180
supplementary angles add up to 180
3x+9+6x+27=
3x+9+6x+27=
\,\,180
180
Drop parentheses
9x+36=
9x+36=
\,\,180
180
Combine like terms
-36\phantom{=}
−36=
\,\,-36
−36
9x=
9x=
\,\,144
144
\frac{9x}{9}=
9
9x
=
\,\,\frac{144}{9}
9
144
Divide both sides by 9
x=
x=
\,\,\color{green}{16}
16
\text{Find the measure of }\angle A:
Find the measure of ∠A:
\text{m}\angle A=
m∠A=
\,\,3x+9
3x+9
Given
\text{m}\angle A=
m∠A=
\,\,3(\color{green}{16})+9
3(16)+9
Plug in x
\text{m}\angle A=
m∠A=
\,\,48+9
48+9
Multiply
\text{m}\angle A=
m∠A=
\,\,57
57
Combine
