Step-by-step explanation:
In an equilateral triangle, all the three sides are equal as well as all the angles are equal. Let the angles be x.
We know that the sum of angles of a triangle is equal to 180 degrees. It means that,
x+x+x=180
3x=180
x=60°
Hence, if a triangle is an equilateral triangle, then the triangle has exactly three 60° angles. Hence, △ABC is an equilateral triangle
For my answer i got y = x - 18

Let AB be a chord of the given circle with centre and radius 13 cm.
Then, OA = 13 cm and ab = 10 cm
From O, draw OL⊥ AB
We know that the perpendicular from the centre of a circle to a chord bisects the chord.
∴ AL = ½AB = (½ × 10)cm = 5 cm
From the right △OLA, we have
OA² = OL² + AL²
==> OL² = OA² – AL²
==> [(13)² – (5)²] cm² = 144cm²
==> OL = √144cm = 12 cm
Hence, the distance of the chord from the centre is 12 cm.
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Answer:
<em>The answer is B.</em>
