SUM OF ANGLES YAY!

LEARNING GOALS LG: Demonstrate the understanding that the sum of the angles of all quadrilaterals are the same, and the sum of the angles of all triangles are the same Kid Friendly: Show that you know that the angles of all quadrilaterals add up to 360 degrees, and the angles of all triangles add up to 180 degrees What I think I know:

TRIANGLES The sum of the three angles of a triangle add up to 180 degrees In a triangle, the three angles always add to 180°: A + B + C = 180°

HOW THIS IS HELPFUL Example: Find the Missing Angle "C” Start With: A + B + C = 180° Fill in what we know: 38° + 85° + C = 180° Rearrange C = 180° - 38° - 85° Calculate: C = 57°

QUADRILATERALS The sum of the four angles of a quadrilateral add up to 360 degrees

HOW THIS IS HELPFUL Example: Find the missing angle of A Start with: A + B + C + D = 360 Fill in what you know: A = 360 A = 360 – 120 – 80 – 75 A = A?

COMPARING QUADRILATERALS TO TRIANGLES If you take a quadrilateral you know that all four angles add up to 360degrees total. Inside a quadrilateral you can fit TWO triangles. Let’s look at this:

PRACTICE 1.Draw three different triangles. Measure all of the angles. When added up each should equal 180degrees 2.Draw three different quadrilaterals. Measure all of the angles. When added each should equal 360degrees

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