1. Lesson 6.3/6.4 Objective: To find the two missing lengths of a 30°- 60°- 90°triangle. To classify four sided polygons. In a 30°-60°-90° triangle, The hypotenuse (C) is always twice as long as the side opposite the 30° angle (a). (Short Side is half the hypotenuse) a c b 60° 30° 2a = c a = c In a 30-60-90 triangle find the indicated length 1) a if c = 20 2) c if a = 4 3) a if c = 12 a = 10 c = 8 a = 6

2. Find the lengths of the 30-60-90 triangle. 30 60 4 c b c = 2a c = 2(4) c = 8 =8 4 2 + b 2 = 8 2 16 + b 2 = 64 b 2 = 48

3. 30 60 4 a b Determine the length of a and b a = half of 4 a = 2

4. Quadrilaterals Vocabulary: Quadrilateral: A polygon with four sides and four angles. We will study six types of Quadrilaterals. Square: Four right angles. Four congruent sides. Opposite sides are parallel. All four angles added together =360 90 + 90 + 90 + 90 = 360

5. Trapezoid: Four sides with only one pair of opposite parallel sides. 80 100 100 + 100 + 80 + 80 = 360 Parallelogram: Four sides with both pairs of opposite sides congruent and parallel 130 50 130 + 130 + 50 + 50 = 360

6. Rhombus: Parallelogram where all sides are congruent Rectangle: Parallelogram with four right angles. All four sides added together from any quadrilateral will always equal 360° 95 85 x 95 + 95 + 85 + x = 360