Please solve the math question

\[Please\quad tell\quad me\quad the\quad solution\quad of\quad the\quad \\ following\quad question:\\ \\ In\quad \triangle ABC,\quad D\quad is\quad the\quad midpoint\quad of\quad \\ side\quad BC.\quad \angle ACB\quad =\quad { 30 }^{ \circ }.\quad \angle ADB\quad =\quad 45\\ Find\quad \angle BAD.\quad \] I know how to solve it using trigo. But tell me a different method. P.S it's an eighth class question.

#Geometry

Easy Math Editor

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.
Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.

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

Math	Appears 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}`	$\boxed{123}$

Comments

Sort by:

Top Newest

DO YOU WANT FULL SOLUTION OR JUST HINT , IF HINT , THEN TRY BY CONSTRUCTION.

ashay wakode - 6 years, 1 month ago

What's your answer, is it 120 ?

Shivam Hinduja - 6 years, 1 month ago

No,it's 30.

ashay wakode - 6 years, 1 month ago

@Ashay Wakode – Your answer is correct

Rajdeep Dhingra - 6 years, 1 month ago

FULL SOLUTION

Rajdeep Dhingra - 6 years, 1 month ago

@ashay wakode Please help

Rajdeep Dhingra - 6 years, 1 month ago

@Sandeep Bhardwaj @Calvin Lin @Steven Zheng @David Mattingly Please help

Rajdeep Dhingra - 6 years, 1 month ago

I believe that this is an NMTC problem. You can view the solution discusssion in this problem. One approach just uses sine rule, while another approach gets more creative.

Calvin Lin Staff - 6 years, 1 month ago

Math	Appears 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}`	$\boxed{123}$