Questions: Determine the value of y in the figure, and identify whether the triangle is isosceles or equilateral.
y=30°; equilateral
y=60°; isosceles
y=30°; isosceles
y=60°; equilateral
Transcript text: Determine the value of $y$ in the figure, and identify whether the triangle is isosceles or equilateral.
$y=30^{\circ}$; equilateral
$y=60^{\circ}$; isosceles
$y=30^{\circ}$; isosceles
$y=60^{\circ}$; equilateral
Solution
Solution Steps
Step 1: Identify the sum of angles in a triangle
The sum of the interior angles in any triangle is always 180 degrees.
Step 2: Set up the equation
Given two angles are 60 degrees each, we can set up the equation to find the third angle \( y \):
\[ 60^\circ + 60^\circ + y = 180^\circ \]
Step 3: Solve for \( y \)
\[ 120^\circ + y = 180^\circ \]
\[ y = 180^\circ - 120^\circ \]
\[ y = 60^\circ \]
Step 4: Determine the type of triangle
Since all three angles are 60 degrees, the triangle is equilateral.