Today's TEKS were: G.3.B The student is expected to construct and justify statements about
geometric figures and their properties.
Today's objective was: The student will be able to classify triangles based on measurement of angles or sides.
Review of today's lesson: There are two ways to classify triangles. You can group triangles by their angle measurement or by their side measurement.
When grouping triangles by angles, they can be acute, right, obtuse, or equiangualar. An acute triangle is a triangle where all of the angles are acute or less than 90 degrees. A right triangle is a triangle that contains one right angle which is an angle equal to 90 degrees. A obtuse triangle contains one obtuse angle or an angle that measures more than 90 degrees. We learned in class today that the that the root equi means equal so, an equiangualar triangle is one where all angles are the same.
When grouping triangles by side length, they can be scalene, isosceles, and equilateral. A scalene traingle triangle where all of the sides are a different size. An isosceles triangle has two side that are the same size. Finally a equilateral triangle is one where all the sides are equal.
You can use a word from both category to describe a triangle. For example, a right scalene triangle is a triangle with a right angle and three different sizes.
Look at this helpful graphic I found.
Cool picture! I like how all the triangles make a rectangle!
ReplyDeleteDid anybody understand when you can choose more than one word from the angles list? I think it's only when the triangle is acute and equiangular, but I'm not sure if there are other times.
Rachel that is the only time I can think of that you could use two angle descriptions for one triangle.
ReplyDeleteI think you're right, Rachel. The day I scribed, we learned about the Angle Sum Theorem, which says that the interior angles of a triangle must add up to 180 degrees. So if a triangle is going to be equiangular, all the angles must be 60 degrees. That's the only way it will work. Therefore equiangular triangles are also acute, and I think that's the only time you pick more than one word from the angles list.
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