Solve for the unknown angle measure θ.
A. θ=112.5
B. θ=120
C. θ=144
D. θ=150

In the given polygon-
>>Two of the angles are of 90⁰
The sum of all angle in n-sided polygon is given by -
[tex]\green{ \underline { \boxed{ \sf{(n-2)\times180}}}}[/tex]
Here number of sides,n = 8
So ,the sum of all angle = [tex]\sf (8-2)\times 180[/tex]
[tex]\sf \implies 6 \times 180[/tex]
[tex]\sf \implies 1080 \degree[/tex]
>>Since two of the angles are of 90⁰ ,let's subtract them from total angle sum to get angles in term of [tex]\theta[/tex] only.
[tex]\implies \sf 1080- 2\times 90[/tex]
[tex]\implies \sf 1080- 180[/tex]
[tex]\implies \sf 900 \degree [/tex]
Now, Sum of remaining 6 angles = 6[tex]\theta[/tex]
Also, 6[tex]\theta[/tex] = 900⁰
[tex]\theta = \dfrac{900}{6}[/tex]
[tex]\theta = 150 \degree[/tex]
Answer:
heya ^^
let's first see what the question says -
so , we're given an octagon and the figure states that two of the angles of the octagon are of measure 90°.
while , rest of the angles have been named [tex] \bold{\theta }[/tex] and this thing clears that all the other angles are of equal measure.
now , angle sum property of octagon states that the sum of all the angles of an octagon equals 1080.
therefore ,
[tex]\bold{90 \degree + 90 \degree + \theta+ \theta+ \theta+ \theta+ \theta+ \theta = 1080 \degree }\\ \\ 180\degree + 6\theta = 1080\degree \\ \\ 6\theta = 1080\degree - 180\degree \\ \\ 6\theta = 900\degree \\ \\ \theta = \frac{900}{6} \\ \\ \underline\bold\pink{\: \theta = 150\degree}[/tex]
therefore ,
option ( D ) θ=150 is correct.
hope helpful :D