Step-by-step explanation:
a) The circumference of a circle is 360 degrees. so:
7x+15+8x+6x+30=360
21x+45=315
21x=135
x=15
b) This means 7(15)+15=120, 8(15)=120, and 6(15)+30=120. Thus, by the inscribed angle theorem, all the angles measure 60 degrees, and the triangle is thus equilateral and isosceles.
