1) given the following diagram, is 1 a supplement of cof? yes or no? 2) given the following diagram, if m∠cof  = 150°, then m∠boc  = < ad> (upside down t) < bf> a)  150°b) 90°c) 45°d) 30°(link for questions)

1. Supplementary angles : Two angles are supplementary if their sum is 180°.

For angle 1 and ∠COF to be supplementary,

∠1 + ∠COF =180°

must be satisfied.

We see in the figure that angle 1 and COF form a straight line.

The angle of a straight line is 180°.

∴ 1 is a supplement of ∠COF.

Answer : YES

2. Given : ∠COF =150° ;

AD is perpendicular to BF.

Here, ∠BOC + ∠COF = 180° , since they form a straight line.

∠BOC = 180° - ∠COF = 180° - 150° =30°

∴ ∠BOC = 30°

Answer : D. 30°