<u>3/4</u> = 1/2 + 1/4
<u>5/8</u> = 1/2 + 1/8
<u>7/12</u> = 1/2 + 1/12
NOT NECESSARILY would a triangle be equilateral if one of its angles is 60 degrees. To be an equilateral triangle (a triangle in which all 3 sides have the same length), all 3 angles of the triangle would have to be 60°-angles; however, the triangle could be a 30°-60°-90° right triangle in which the side opposite the 30 degree angle is one-half as long as the hypotenuse, and the length of the side opposite the 60 degree angle is √3/2 as long as the hypotenuse. Another of possibly many examples would be a triangle with angles of 60°, 40°, and 80° which has opposite sides of lengths 2, 1.4845 (rounded to 4 decimal places), and 2.2743 (rounded to 4 decimal places), respectively, the last two of which were determined by using the Law of Sines: "In any triangle ABC, having sides of length a, b, and c, the following relationships are true: a/sin A = b/sin B = c/sin C."¹
Answer:
A, C, F
Step-by-step explanation:
Definition: The circumcenter is the center of the triangle's circumcircle - the circle that passes through all three of the triangle's vertices. If point H is the circumcenter of the triangle DEF, then the circumcircle passes through its vertices D, E and F (option A is true).
Option B is false, the circumcircle doesn't pass through the points L, M and N. This option is true for inscribed circle, not for circumcircle.
Option C is true, because HD and HE are the radii of the circumcircle.
Option D is false. This option is true for inscribed circle, not for circumcircle.
Option E is false. This option is true for inscribed circle, not for circumcircle.
Option F is true, because both these angles are right angles.
