414,630 views
28 votes
28 votes
I need help I don’t understand this question. DC=8.5, DW=6.

I need help I don’t understand this question. DC=8.5, DW=6.-example-1
User Yong Wang
by
2.0k points

1 Answer

16 votes
16 votes

Recall that the diagonals of a square bisect each other, therefore:


BW=DW=6.

The diagonals are congruent, therefore:


AC\cong DB=2DW=2(6)=12.

To compute DA we use the fact that the figure is a square:


DA=DC=8.5.

Now, we know that the angles at the vertices are right angles, therefore:


m\angle ABC=90.

To determine the measure of angles ABD, and DCA we use the trigonometric function sine:


\begin{gathered} sin(\angle ABD)=(DA)/(DB)=(√(287))/(2(12)), \\ sin(\angle DCA)=(DA)/(CA)=(√(287))/(2(12)). \end{gathered}

Therefore:


m\angle ABD=m\angle DCA\approx45^(\circ).

Finally, to determine the measure of angle DWA, we use the fact that the figure is a square, therefore the diagonals bisect each other at 90° angles.

Answer:


\begin{gathered} BW=6, \\ AC=12, \\ DA=8.5, \\ m\angle DWA=90^(\circ), \\ m\angle ABC=90^(\circ), \\ m\angle ABD=45^(\circ), \\ m\angle DCA=45^(\circ). \end{gathered}

User Maynard
by
2.7k points