ABCD is a rhombus and DEFG is a square. Find $\angle\text{FHD}$. Ans: ___

1. Find the interior angle $\angle\text{ADC}$ of the rhombus.

In rhombus ABCD, opposite angles are equal.
$\angle\text{ADC} = \angle\text{CBA} = 75^\circ$

2. Find $\angle\text{CDE}$ using the given reflex angle.

Angles at a point sum to $360^\circ$.
$\angle\text{CDE} = 360^\circ - 260^\circ = 100^\circ$

3. Find $\angle\text{ADE}$ and then $\angle\text{FHD}$.

$\angle\text{ADE} = \angle\text{CDE} - \angle\text{ADC} = 100^\circ - 75^\circ = 25^\circ$
In $\triangle\text{DHE}$, $\angle\text{DEH} = 90^\circ$ (interior angle of square DEFG).
$\angle\text{FHD}$ is an exterior angle to $\triangle\text{DHE}$.
$\angle\text{FHD} = \angle\text{ADE} + \angle\text{DEH} = 25^\circ + 90^\circ = 115^\circ$