Today in grade five we talked about classifying triangles according to angle measures. There are three types of triangles based on angle measures:
Remember....
To be classified as right-angled, the triangle needs ONLY ONE RIGHT ANGLE.
To be classified as obtuse-angled, the triangle needs ONLY ONE OBTUSE ANGLE.
To be classified as acute-angled, the triangle needs ALL ACUTE ANGLES.
This makes sense because we know the sum of the three angles in a triangle is 180 degrees.
You must also be able to measure the size of the three angles in a triangle with a protractor.
In grade four, we began our discussion of QUADRILATERALS. A quadrilateral is a four-sided polygon. A polygon is any shape with straight sides and is closed.
Some definitions you MUST LEARN:
A parallelogram is a quadrilateral with opposites parallel and equal.
A rectangle is a parallelogram with four right angles.
A rhombus is a parallelogram with all equal sides.
A square is a parallelogram with all equal sides and four right angles.
According to our definitions, there are multiple ways you can name parallelograms.
A square is special. It has the same properties as rectangles and rhombuses.
A trapezoid is a quadrilateral with ONLY ONE SET OF PARALLEL SIDES.
There are different kinds of trapezoids. A right trapezoid has two right angles as well as one set of parallel sides. An isosceles trapezoid has two equal sides as well as one set of parallel sides.
A kite is a quadrilateral with TWO PAIRS OF ADJACENT SIDES EQUAL. In a kite opposite sides are NOT EQUAL.
Here is a quadrilateral tree that sorts them by properties:
Take some time to learn the definitions. Make sure you understand the markings.
Reminders:
- Bring all your materials for your habitat project tomorrow. DON'T FORGET. You will be given as long as you need on Friday to complete this task. Enjoy the chance to show off your creative talents. Some of the animals combinations are fantastic!
