Question

With a ruler and compass, which of the following angles cannot be constructed?

• A. ${80}^{\circ }$
• B. ${60}^{\circ }$
• C. ${90}^{\circ }$
• D. ${105}^{\circ }$

Answer 1

The correct option is A

${80}^{\circ }$

With a ruler and compass we can construct ${15}^{\circ }$, ${30}^{\circ }$, ${45}^{\circ }$, ${60}^{\circ }$, ${90}^{\circ }$, ${105}^{\circ }$ angles. We cannot construct a ${80}^{\circ }$.