Question

1300 960 760 70° Determine the value of x in the pentagon shown above. (G.10)(1 point) O A. 128° OB. 108° O C. 80° O D. 168°

Answer 1

A. 128º

1) Given that the Sum of the Interior angles can be calculated by this formula below, let's do it. A Pentagon has 5 sides

$\begin{gathered} S_I=180(n-2) \\ S_I=180(5-2) \\ S_I=540^{\circ} \end{gathered}$

2) Examining that figure, we have a linear pair between

∡70º and that adjacent angle, let's call it "y" so

70 +y = 180

y=110º

Now we can write an equation to find that angle x

x +130+96+110+76= 540

x+412=540

x=540-412

x= 128º

3) So the answer is A 128º