# Help Me In Geometry Problem

Here, AD=BD , BM=CM. BC=$$1$$.What is the area of the triangle which is marked with U

Note by Fazla Rabbi
4 years, 8 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:

There are two D's in the problem, so let the D on AB be $$N$$. Let $$O=DM\cap CN$$.

We must find $[DNO]=[DNC]-[DOC]$ Since the sidelength is 1, $$[DNC]=\dfrac{1}{2}$$. Since $$\triangle DNC\sim\triangle DCM$$, $\dfrac{[DNC]}{[DCM]}=\dfrac{DC^2}{DM^2}=\dfrac{1}{\dfrac{5}{4}}=\dfrac{4}{5}$ Also, $$[DCM]=\dfrac{1}{4}$$, so $$[DOC]=\dfrac{1}{5}$$. Therefore, the answer is $\dfrac{1}{2}-\dfrac{1}{5}=\boxed{\dfrac{3}{10}}$

- 4 years, 8 months ago

There is something special about triangle U. See if anyone else can figure it out. Hint: right triangle

- 4 years, 8 months ago

.3

- 4 years, 7 months ago