Question

For a triangle, choose the incorrect option.

• A. It has no diagonal.
• B. Any two sides are adjacent sides.
• C. Any two angles don't share a common side.
• D. Any two sides share a common vertex

Answer 1

The correct option is C Any two angles don't share a common side.

A triangle has three sides. So, it has no diagonals.
So, option A can be neglected.

A triangle has three sides. So, any two sides can be considered as adjacent to each other.
So, option B can also be neglected.

A triangle has three sides. So, any two sides meet an one vertex. Hence, any two sides share a common vertex.
So, option D can also be neglected.

Any two angles of a triangle always have a common side.
So, the correct answer is option C.