McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
2. Parallelograms
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Exercise 4 Page 489

Recall the theorem referenced in the book that states if a quadrilateral is a parallelogram, then its diagonals bisect each other.

a=9, b=8

Practice makes perfect

We want to find the values of a and b for the parallelogram WXZY, using the given algebraic expressions for the segment lengths. For convenience, we will label the point of intersection of the diagonals T.

Recall the following theorem.

Parallelogram Diagonals Theorem

If a quadrilateral is a parallelogram, then the diagonals bisect each other.

Therefore, the following segments are congruent. WT ≅ TZ and YT ≅ TX By the definition of congruent segments, we can conclude that their lengths are equal. WT = TY and ZT = TX Let's create two equations by substituting the lengths of the segments into these equations. 2=a-7 and 10=2b-6 Let's start by solving the first equation for a.
2 = a - 7
9 = a
a = 9
Now, we can find the value of b by solving the second equation.
10 = 2b - 6
16 = 2b
8 = b
b = 8