Question

please help my teacher never explains anything i need help

Answer 1

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

$\frac{21 \sqrt{2} }{2}$

Because a side that in a 45 45 triangle is

$\frac{ \sqrt{2} }{2}$

times more than the hypotenuse.

Answer 2

Answer:

the answer is A

Step-by-step explanation:

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