Răspuns:
AB║CD ⇒ m(arcAD)=m(arcBC)
a) m(arcBC)=[360°-m(arcAB)-m(arcCD)]:2=(360°-72°-144°):2=(360°-216°):2=72°
b) m(arcAD)=[360°-m(arcAB)-m(arcCD)]:2=(360°-59°-125°):2=(360°-184°):2=88°
Explicație pas cu pas:
