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A kite is a quadrilateral with exactly two pairs of congruent consecutive sides. Example 1:.
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A kiteis a quadrilateral with exactly two pairs of congruent consecutive sides.
Example 1: Lucy is framing a kite with wooden dowels. She uses two dowels that measure 18 cm, one dowel that measures 30 cm, and two dowels that measure 27 cm. To complete the kite, she needs a dowel to place along . She has a dowel that is 36 cm long. About how much wood will she have left after cutting the last dowel? N 36 – 32.4 3.6 cm left
In kite ABCD, mDAB = 54°, and mCDF = 52°. Find mBCD. Example 2A: Kite cons. sides ∆BCD is isos. 2 sides isos. ∆ isos. ∆base s CBF CDF mCBF = mCDF Def. of s Polygon Sum Thm. mBCD + mCBF + mCDF = 180° mBCD + mCBF+ mCDF= 180° mBCD + 52°+ 52° = 180° mBCD = 76°
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.
If the legs of a trapezoid are congruent, the trapezoid is an isosceles trapezoid. The following theorems state the properties of an isosceles trapezoid.
Example 3a Find mF. mF + mE = 180° Same-Side Int. s Thm. E H Isos. trap. s base mE = mH Def. of s mF + 49°= 180° Substitute 49 for mE. mF = 131° Simplify.
Example 3b JN = 10.6, and NL = 14.8. Find KM. Isos. trap. s base Def. of segs. KM = JL JL = JN + NL Segment Add Postulate KM = JN + NL Substitute. KM = 10.6 + 14.8 = 25.4 Substitute and simplify.
Example 4 Find the value of x so that PQST is isosceles. Trap. with pair base s isosc. trap. Q S mQ = mS Def. of s Substitute 2x2 + 19 for mQ and 4x2 – 13 for mS. 2x2 + 19 = 4x2 – 13 Subtract 2x2 and add 13 to both sides. 32 = 2x2 Divide by 2 and simplify. x = 4 or x = –4
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.
Example 5A Find EF. Trap. Midsegment Thm. Substitute the given values. Solve. EF = 10.75
Example 5B 1 16.5 = (25 + EH) 2 Find EH. Trap. Midsegment Thm. Substitute the given values. Simplify. Multiply both sides by 2. 33= 25 + EH Subtract 25 from both sides. 13= EH