# Geonetry

square $$ABCD$$ divided into 18 smaller square.
17 squares of the sides of length 1.
$$ABCD$$ square area Find.

2 years, 2 months ago

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold
- bulleted- list
• bulleted
• list
1. numbered2. list
1. numbered
2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in $$...$$ or $...$ to ensure proper formatting.
2 \times 3 $$2 \times 3$$
2^{34} $$2^{34}$$
a_{i-1} $$a_{i-1}$$
\frac{2}{3} $$\frac{2}{3}$$
\sqrt{2} $$\sqrt{2}$$
\sum_{i=1}^3 $$\sum_{i=1}^3$$
\sin \theta $$\sin \theta$$
\boxed{123} $$\boxed{123}$$

Sort by:

Let area of ABCD be $$x^2$$ and area of the last of the 18 squares be $$y^2$$.

We have $$x^2=17+y^2$$ or $$(x+y)(x-y)=17$$. We must have $$x+y=17$$ and $$x-y=1$$.

Solving we get $$x=9$$ and $$y=8$$.

Therefore area of ABCD is $$9^2=81$$.

- 2 years, 2 months ago

Actually, x^2=17+y^2 if I'm not mistaken because there are seventeen squares of side length one. Therefore the area is 81. At least I know this case works because it can be drawn out. Maybe the wording messed one of us up.

- 2 years ago

Yes you are right thanks.

- 2 years ago