Question

How would you write the reversible statement as a Biconditional?

Answer 1

This is math, not English, but okay xD 
"Two intersecting lines are perpendicular if and only if they form four 90 degree angles" would be my answer.

Answer 2

Biconditional statement contains the phrase "if and only if".

Among the choices only Choice A has the phrase "if and only if". Thus, the reversible statement "If two perpendicular lines intersect, they form four 90 degrees angles" will be written as A) TWO INTERSECTING LINES ARE PERPENDICULAR IF AND ONLY IF THEY FORM FOUR 90 DEGRESS ANGLES is a biconditional statement.