Question

state a counterexample to the definition below: a figure with four right angles is a square. a rectangle has four right angles. a figure with four right angles is a square. a square has four equal sides. a triangle has three angles.

Explanation:

A triangle has three angles, not three right - angles. A square has four equal sides and four right angles. A rectangle has four right angles but not necessarily four equal sides. A figure with four right angles is not always a square as it could be a rectangle. So, the statement "A triangle has three angles" is correct and not a counter - example. The statement "A square has four equal sides" is correct and not a counter - example. The statement "A figure with four right angles is a square" is incorrect as a rectangle is a counter - example. A rectangle has four right angles but is not a square (unless it has equal sides too).

Answer:

A rectangle has four right angles.