Math Is Fun Forum

viggi

Member

Registered: 2015-06-06

Posts: 1

Help

Could someone help me with the solution for the following please:

Image added by bobbym.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Help

Hi;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

math9maniac

Member

From: Tema

Registered: 2015-03-30

Posts: 443

Re: Help

Hi viggi;

Welcome to the forum. Glad to make your acquaintance. You can tell us about yourself in the Introductions section.

---

Only a friend tells you your face is dirty.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,144

Re: Help

hi viggi

Welcome to the forum.

I'm assuming here that the three measurements are for the triangle ABC and the angle at D is 90.

The quadrilateral ADEC is a difficult one to work with so I changed the given information to this:

area BDE = ½ area ABC.  Now we can work just with the area of triangles.

There are three useful formulas that can be used here for the area of a triangle:

Heron's formula:

and the usual one:

So I can make these equations:

So:

Also

So eliminate EB^2

eliminate DB^2

Hope that helps,

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob