Question

Which of the following angles can not be constructed using a ruler and compasses?

• A. ${75}^{\circ }$
• B. ${90}^{\circ }$
• C. ${135}^{\circ }$
• D. ${85}^{\circ }$

Answer 1

The correct option is D

${85}^{\circ }$

As we know that we can construct only those angle using ruler and compasses which are multiple of 15.

Here ${75}^{\circ }$ , ${90}^{\circ }$ and ${135}^{\circ }$ are the multiple of 15 but ${85}^{\circ }$is not a multiple of 15.Hence we can not construct ${85}^{\circ }$ angle using ruler and compasses.