Triangles in the Ocean

This is Daniel! He has been researching Greece and has already noticed a lot of triangles. His teacher has challenged him to draw pictures of the sea creatures that can be found in the Mediterranean Sea . . . using only triangles!

Daniel saw a sea turtle, so he drew a sea turtle on his canvas. What kinds of triangles did Daniel use to draw the sea turtle?

He has seven right triangles. Each right triangle has one right angle, which is a square corner. Let’s count the right triangles.

1, 2, 3, 4, 5, 6, 7. There are seven right triangles in his sea turtle.

Daniel also uses obtuse triangles to make the turtle. An obtuse triangle has one obtuse angle. Let’s count the obtuse triangles.

1, 2, 3, 4. There are four obtuse triangles.

Next, Daniel drew a stingray. What kinds of triangles did he use to draw the stingray’s body?

The stingray’s body is made of scalene triangles. That means none of the sides are the same length.

What kind of triangle is the stingray’s tail?

The stingray’s tail is an isosceles triangle. That means that two sides of the triangle are the same length.

Next, Daniel drew a huge whale. What kinds of triangles do you see?

Wow, this drawing has a lot of triangles, and they are all equilateral triangles. That means that all of the sides are the same length.

How many equilateral triangles are there? Let’s count them.

1, 2, 3, 4, 5, 6, 7, 8, 9. There are nine equilateral triangles.

Daniel also saw a school of fish swimming, so he drew the fish. Can you find the isosceles triangle?

The isosceles triangle is the fish’s tail! There is also one in the middle of the fish. Both triangles have two sides that are the same length.

Can you find an obtuse triangle?

Remember that an obtuse triangle has one angle that is greater than 90 degrees. There are actually several obtuse triangles in the fish. In this case, one triangle is both isosceles and obtuse because it has an obtuse angle and two sides that are the same length.

The last sea creature Daniel drew was a squid! He used many triangles for the tentacles. What kinds of triangles are these tentacles?

They are acute triangles! Acute triangles are triangles in which all three angles are less than 90 degrees.

Daniel sure has filled up his canvas with sea creatures made of triangles! He used all of the different kinds of triangles for his masterpiece!