Answer:
YD=6.9
Step-by-step explanation:
In an isosceles trapezoid both diagonals have an equal length. Given this, since diagonal AC is equal to 17.2, diagonal BD must be equal to 17.2. Diagonal BD is made up of segments BY and YD, so the lengths of BY and YD must add to equal 17.2. Since BY is 10.3, the equation YD+10.3=17.2 can be used to find the value of YD. To solve this, subtract 10.3 from both sides of the equation to find that YD is equal to 6.9.
