Basic Mathematics
# Angles and Lines

How many **acute** angles does an **obtuse** triangle have?

$A,$ $B,$ and $C$ lie on a straight line. If $\color{#3D99F6}{ \angle ACD ={151}^\circ},$ which of the following is true of $\color{#D61F06} { \angle BCD}$?

In the above diagram,

$A$, $B$, and $C$ lie on a straight line. Which of the following is true of angle $\angle BAC$?

In the above diagram,