Transcript text: What is the value of $z$ ?
\[
z=\square^{\circ}
\]
Solution
Solution Steps
Step 1: Find the measure of angle IHG.
Quadrilateral FIGH is an isosceles trapezoid, so $FI \parallel HG$. The angles $FIH$ and $GHI$ are supplementary, so
$m\angle IHG + m\angle FIH = 180^\circ$
$m\angle IHG + 50^\circ = 180^\circ$
$m\angle IHG = 180^\circ - 50^\circ$
$m\angle IHG = 130^\circ$
Step 2: Find the measure of angle IGH.
The sum of the angles in quadrilateral FIGH is $360^\circ$. Since $FI=FH$ and $GH=FG$, it is an isosceles trapezoid, and $m\angle GFI = m\angle HFG=z$ and $m\angle FIH=50^\circ$ and $m\angle FHG=98^\circ$.
The sum of the angles in the quadrilateral is $360^\circ$. So, $z+z+50+98 = 360$.
$2z+148=360$
$2z = 360 - 148$
$2z = 212$
$z = \frac{212}{2}$
$z=106$
Step 3: Find the measure of angle FIG.
The sum of the angles in triangle FIG is $180^\circ$. So,
$m\angle FIG + m\angle IGF + m\angle GFI = 180^\circ$
$50^\circ + m\angle IGF + z = 180^\circ$
$50^\circ + m\angle IGF + 106 = 180^\circ$
$156^\circ + m\angle IGF = 180^\circ$
$m\angle IGF = 180^\circ - 156^\circ$
$m\angle IGF = 24^\circ$.
The sum of the angles in the quadrilateral FIGH is $360^\circ$.
$50+z+x+98=360$
$148 + 2z=360$
$2z = 212$
$z=106$