Question

If you know that
`m\angle EHF=90^(\circ)` and that
`m\angle GHF=90^(\circ)`, what property/properties can you use to prove that
`m\angle EHF=m\angle GHF`? Explain your answer.

Answer 1

I would use Euclid's first axiom:

Explanation:

Things that are equal to the same thing are equal to each other.

`\begin{array}{rcl}m\angle EHF & = & 90^(\circ) \text{ (Given)}\\m\angle GHF & = & 90^(\circ) \text{ (Given)}\\\therefore m\angle EHF & = & m\angle GHF \text{ (Euclid Axiom 1)} \\\textbf{QEF} & & \\\end{array}`