Question

answer attempt 1 out of 2
$d=square^{circ}$ $e=square^{circ}$ $f=square^{circ}$

Explanation:

Step1: Identify right - angle property

Since the symbol for a right - angle is shown at $d$, by definition of a right - angle, $d = 90^{\circ}$.

Step2: Use linear - pair property

Angles $e$ and the $100^{\circ}$ angle form a linear pair. A linear pair of angles sums to $180^{\circ}$. So, $e=180 - 100=80^{\circ}$.

Step3: Use vertical - angle property

Angles $e$ and $f$ are vertical angles. Vertical angles are equal. So, $f = e=80^{\circ}$.

Answer:

$d = 90^{\circ}$
$e = 80^{\circ}$
$f = 80^{\circ}$