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Aim: What are the properties of a rhombus and a square?. Pythagorean Theorem. a 2 + b 2 = c 2. Do Now:. Find the length of AD in rectangle ABCD, if AB = 2 and diagonal BD = 4. ABD is a right triangle. A rectangle has 4 right angles. a 2 + b 2 = c 2. 2 2 + x 2 = 4 2.
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Aim: What are the properties of a rhombus and a square? Pythagorean Theorem a2 + b2 = c2 Do Now: Find the length of AD in rectangle ABCD, if AB = 2 and diagonal BD = 4. ABD is a right triangle A rectangle has 4 right angles. a2 + b2 = c2 22 + x2 = 42 4 + x2 = 16 x2 = 12
Properties of a Rhombus A rhombus is a parallelogram that has two congruent consecutive sides. A rhombus has all the properties of a parallelogram, PLUS, A rhombus is equilateral. The diagonals of a rhombus are perpendicular to each other. The diagonals of a rhombus bisect its angles
Properties of a Quadrilaterals Property Parallel. Rectangle Rhombus All sides are Opposite sides are Opposite sides are | | Opposite angles are All angles are right Diagonals bisect each other Diagonals are Diagonals are Each Diagonal bisects opposite
Model Problem 500 Find the measures of the numbered angles in the rhombus 900 1 900 500 3 2 500 4 400 The diagonals of a rhombus are perpendicular to each other. 1 = 900 Diagonals of a rhombus are Perpendicular 2 = 500 Alternate Interior s 3 = 500 Diagonals of rhombus bisect the s 4 = 400 The sum of the s of a D equal 1800
Regents Question Inthe diagram below of rhombus ABCD, m∠C = 100. What is m∠DBC? 40o 40o
Model Problem Find the value of the variables (2x)º (x + y)º (3z)º Since all sides are congruent this quadrilateral is a rhombus. Property Parallel. Rectangle Rhombus Diagonals are 2x = 90 x = 45 3z = 90 z = 30 x + y = 90 45 + y = 90 y = 45
D C B A Model Problem Given: ABCD is a parallelogram AB = 2x + 1, DC = 3x – 11, AD = x + 13 Explain how and why ABCD is a rhombus Plan: Show that 2 consecutive sides are congruent. (AB AD) Since ABCD is a parallelogram, opposite sides are equal in length. DC = AB 3x – 11 = 2x + 1 3x – 2x = 11 + 1 x = 12 Substitute x = 12 to find the length of AB and AD: AB = 2x + 1 = 2(12) + 1 = 25 AD = x + 13 = 12 + 13 = 25 AB AD. Since parallelogram ABCD has two consecutive congruent sides, it’s a rhombus.
Aim: What are the properties of a rhombus and a square? Do Now: In rhombus KLMN, KL = 3x, LM = 2(x + 3). Find the length of each side of the rhombus. L M K N
Properties of a Square A B A square is a rectangle that has two congruent sides. D C A square has all the properties of a rectangle, PLUS, A square has all the properties of a rhombus.
Properties of a Square Property Parallel. Rhombus Rectangle Square All sides are Opposite sides are Opposite sides are | | Opposite angles are All angles are right Diagonals bisect each other Diagonals are Diagonals are Each Diagonal bisects opposite
Model Problem ABCD is a square with diagonal BD. Determine if True or False. A. AB BC B. AB CD C. AB AC D. 1 2 E. 1 3 F. B 4 G. ABC is isosceles H. ABC is right triangle I. ABC ACD TRUE TRUE FALSE TRUE TRUE FALSE TRUE TRUE TRUE
Model Problem Find the value of the variables. 1 = 3y – 6 x = 5 y = 32 9x 6z 1 x = 7.5 In a square: diagonals are to each other diagonals bisect opposite angles
Model Problem ABCD is a square. If AB = 8x – 6 and BC = 5x + 12, find the length of each side of the square. • Which statement is false? • a square is a rectangle • a square is a rhombus • a rhombus is a square • a square is a parallelogram
Model Problem In square ABCD diagonal AC is drawn. How many degrees are there in the measure of ACB? If the side of a square is 4, find the length of the diagonal.