What is the answers to 2a 2b and 2c ?

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.

The answer is (a) 12-2(-1)(6)2(6)=12