Question Video: Identifying Polygons from a Description of their Angles

Pick the shape that Isabella is describing.

02:10

Video Transcript

Pick the shape that Isabella is describing.

Isabella tells us two things about this shape. Firstly, she tells us that it has five angles. Let’s look at the four shapes that we’ve been given. If we count the number of angles inside the first shape, it does indeed have five angles. So, the first shape is still a possibility. Let’s look at the second shape, the blue shape.

The second shape, which looks like a square but could possibly be a rectangle, only has four angles inside of it. So, the second shape is not a possibility for the shape that Isabella is describing. Let’s look at the orange shape.

Inside this shape, there are also five angles, so this shape is still a possibility for the one Isabella is describing.

Finally, let’s count the angles inside the green shape. It also has five angles. And therefore, this shape is still a possibility.

So, we’re left with three shapes; the pink one, the orange one, and the green one. Let’s look at the second fact that Isabella has given us. She tells us that three of the angles are right angles. Right angles are angles of 90 degrees. Let’s look at the three remaining shapes and see if they do have three right angles.

The pink shape doesn’t have any right angles. All of its angles are obtuse angles. Therefore, Isabella isn’t describing the pink shape. Let’s look at the orange shape.

The orange shape doesn’t have any right angles either. Four of its angles are acute angles and one is a reflex angle. Isabella isn’t describing the orange shape either. Let’s look at the green shape.

The green shape has two obtuse angles. And it also has the three right angles that we’re looking for. One, two, three. Therefore, Isabella is describing the green shape.

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.