a).
The shape has 5 sides. The inside angles of every 5-sided shape
(pentagon) add up to 540 degrees.
The 3 angles given add up to (110 + 109 + 100) = 319 .
The two leftover angles add up to (540 - 319) = 221 degrees.
They're not equal, so we can't tell how the 221 breaks down between them.
b).
The shape has 4 sides. The inside angles of every 4-sided shape
add up to 360 degrees.
The 3 angles given add up to (85+ 92 + 93) = 270 degrees.
The fourth angle is (360 - 270) = 90 degrees, even though it doesn't look like it.
c).
The shape has 6 sides. The inside angles of every 6-sided shape
add up to 720 degrees.
The 4 angles given add up to (120 + 110 + 105 + 110) = 445 degrees.
The two leftover angles add up to (720 - 445) = 275 degrees.
They're not equal, so we can't tell how the 275 breaks down between them.
