Both circles have the same center. The circumference of the inner circle is 12.56 inches. What is the area if the shaded region?​

In triangle abc segment de is parallel to the side ac . (the endpoints of segment de lie on the sides ab and bc respectively). find de, if ac=20cm, ab=17cm, and bd=11.9cm;

A. 90 degrees b. 45 degrees c. 30 degrees d. 120 degrees

Solve x+3y=6 and 4x-6y=6 by elimination . show work !