- #1

LogarithmLuke

- 83

- 3

## Homework Statement

Picture: http://matematikk.net/res/eksamen/1T/kort/1T_V11.pdf

Task 5, the one the with a triangle inside a square. I'ts not in English so i'll transalate. I managed to do task a

The picture above shows a square ABCD. The sides in the square have length 1. E is the center of BC, and F is the center of CD.

B Show that the area of triangle AEF is 3/8

C Show that sin a=3/5

## Homework Equations

area of a sqaure: s*s area of a triangle: 0.5*b*h or 0.5*a*b*sin angle

## The Attempt at a Solution

At first I tried to find all the sides of the triangle, but i can't find a way to calculate EF. It also makes it hard when you have to mix a lot with the fractions and answers to get the answer they want. That makes it extra hard to find a solution. Task c i really had no idea, sinus is only usable for right triangles as far as i know. (not the sinus sentence)

I find these kinds of tasks very hard, so if you know of any place to learn geometry that would be nice also :)