Question

Please help my teacher never explains anything i need help

Answer 1

the answer is A

Explanation:

Becuase it has a 45 45 and 90 angles and it also matches the equation

Answer 2

A is the answer.

Since DF=EF, that means angle D and angle E are equal to each other,( Isolcles Triangle Theorem).

Since one of the angle is 90, and the other angles are equal to each other.

`90 + x + y = 180`

`x = y`

so

`90 + x + x = 180`

`2x = 90`

`x = 45`

So the other two missing angles is 45

This makes the triangle a 45-45-90 triangle.

So this means the side DF and EF are

`(21 √(2) )/(2)`

Because a side that in a 45 45 triangle is

`( √(2) )/(2)`

times more than the hypotenuse.