55,623 views
29 votes
29 votes
For rectangle ABCD, if DC =16.4 ft and BC = 14.8 ft, find DB+AC

For rectangle ABCD, if DC =16.4 ft and BC = 14.8 ft, find DB+AC-example-1
User Kevin Liu
by
2.5k points

1 Answer

19 votes
19 votes

Recall that one property of a rectangle is that opposite sides are always equal.

Therefore, we can say that:

DC = AB

BC = AD

Because of this, we can also say that DB = AC.

Given:

DC = 16.4 ft.

BC = 14.8 ft.

Using the Pythagorean Theorem, let's find DB.


\begin{gathered} \text{ c}^2=a^2+b^2 \\ \text{ DB}^2=DC^2+BC^2 \\ \text{ DB}^{}=√(DC^2+BC^2) \end{gathered}
\text{ DB = }\sqrt[]{16.4^2+14.8^2}\text{ = }\sqrt[]{268.96\text{ + 219.04}}
\text{ DB = }\sqrt[]{488}\text{ }\approx\text{ 22.1 ft.}

Since DB = AC, DB + AC will be:


\text{ DB + AC = DB + DB = 2DB}
\text{ 2(22.1) = 44.2 ft.}

Therefore, DB + AC = 44.2 ft.

The answer is Choice B.

User Sardar Usama
by
3.0k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.