Question

How to solve using area formula?
1. http://prntscr.com/763sih
2. http://prntscr.com/763sor

I don't need the exact answer just a little guidance so I know how to do them
Thanks in advance

Answer 1

@dan815 Any ideas?

Answer 2

For #1 the area of a triangle =
(1/2) * base * height
First we need to find the height of the triangle.
sine 30 = opposite / hypotenuse
the opposite is the height so
height = sine 30 * 30 m
height = .5 * 30
height = 15

area = (1/2) * 42 * 15
area = 315

Answer 3

So basically apply SohCahToa?

Answer 4

I thought I explained it
First you have to solve for the height
Second then use the area formula

Answer 5

Oh, I'm sorry. Thank you.

Answer 6

@wolf1728 doesn't SOHCAHTOA work for special right triangles? I don't see a right triangle in tehre :P

Answer 7

For #1 I mean*

Answer 8

I dropped a perpendicular from point J to point A. This line becomes the height.

Answer 9

@Jhannybean @wolf1728 perhaps using area= 1/2 ab Sin C?

Answer 10

chimber what is a and b?

Answer 11

If you go here:
http://www.1728.org/triang.htm
There is a triangle area formula that states
Area = 1/2 * side 1 * sine (A) * side 2

Answer 12

I might just be confusing myself...

Answer 13

My own guess is that your formula
area= 1/2 ab Sin C
is another version of my formula
Area = 1/2 * side 1 * sine (A) * side 2

Answer 14

As far as applying SohCahToa,
I only needed Soh to determine the height

Answer 15

This is pretty straightforward.
First find the height
Then calculate the area.

Answer 16

Okay, moving on to problem #2
The angle between the 2 known sides is
180 -25 -13 =
142 degrees

Using the area formula
Area = 1/2 * side 1 * sine (E) * side 2
Area = 1/2 * 4 * sine (142) * 8
Area = 1/2 * 4 * 0.61566 * 8
Area = 9.85056

Answer 17

It is, I just solved others like #1 with no hassle. #2 actually seems easier than I thought it would be. Thank you, @wolf1728

Answer 18

Okay, and there's the solution if you need it.