Memory Plane geometry (D)Version en ligne Basic Questions about Geometry par Tatiana Cruz How many sides does a triangle have? How many diagonals does a pentagon have? What type of angle measures exactly 180 degrees? A straight angle measures exactly 180 degrees. What type of angle measures exactly 180 degrees? How many sides does a triangle have? How many right angles are there in a square? A square has four right angles. How many right angles are there in a square? A straight angle measures exactly 180 degrees. A triangle has three sides. How many diagonals does a pentagon have? A triangle has three sides. A square has four right angles.