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6-6 Kites and Trapezoids. Properties and conditions. Kites. A kite is a quadrilateral with exactly two pairs of congruent consecutive sides. Properties of Kites. Trapezoids.
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6-6 Kites and Trapezoids Properties and conditions
Kites A kiteis a quadrilateral with exactly two pairs of congruent consecutive sides.
Trapezoids A trapezoidis a quadrilateral with exactly one pair of parallel sides. Each of the parallel sides is called a base. The nonparallel sides are called legs. Base anglesof a trapezoid are two consecutive angles whose common side is a base.
Isosceles Trapezoids If the legs of a trapezoid are congruent, the trapezoid is an isosceles trapezoid. The following theorems state the properties of an isosceles trapezoid.
Midsegments of Trapezoids The midsegment of a trapezoidis the segment whose endpoints are the midpoints of the legs. In Lesson 5-1, you studied the Triangle Midsegment Theorem. The Trapezoid Midsegment Theorem is similar to it.
Lets apply! Example 1 In kite ABCD, mDAB = 54°, and mCDF = 52°. Find mBCD. Kite cons. sides 2 sides isos. ∆ ∆BCD is isos. isos. ∆base s CBF CDF mCBF = mCDF Def. of s mBCD + mCBF+ mCDF= 180° Polygon Sum Thm.
Lets apply! Example 1 Continued mBCD + mCBF+ mCDF= 180° mBCD + mCDF+ mCDF= 180° Substitute mCDFfor mCBF. mBCD + 52°+ 52° = 180° Substitute 52 for mCDF. Subtract 104 from both sides. mBCD = 76°
Lets apply! Example 2 In kite ABCD, mDAB = 54°, and mCDF = 52°. Find mFDA. CDA ABC Kite one pair opp. s mCDA = mABC Def. of s mCDF + mFDA = mABC Add. Post. 52° + mFDA = 115° Substitute. mFDA = 63° Solve.
Lets apply! Example 3: Applying Conditions for Isosceles Trapezoids Find the value of a so that PQRS is isosceles. S P Trap. with pair base s isosc. trap. mS = mP Def. of s 2a2 – 54 = a2 + 27 Substitute 2a2 – 54 for mS and a2 + 27 for mP. a2 = 81 Subtract a2 from both sides and add 54 to both sides. a = 9 or a = –9 Find the square root of both sides.
Lets apply! Example 4: Applying Conditions for Isosceles Trapezoids AD = 12x – 11, and BC = 9x – 2. Find the value of x so that ABCD is isosceles. Diags. isosc. trap. AD = BC Def. of segs. 12x – 11 = 9x – 2 Substitute 12x – 11 for AD and 9x – 2 for BC. 3x = 9 Subtract 9x from both sides and add 11 to both sides. x = 3 Divide both sides by 3.
1 16.5 = (25 + EH) 2 Lets apply! Example 5 Conditions of Midsegments Find EH. Trap. Midsegment Thm. Substitute the given values. Simplify. 33= 25 + EH Multiply both sides by 2. 13= EH Subtract 25 from both sides.