Please help me! please

1. what is the measure of ∠abc? what is the measure of ∠abd?

What term best describes a line ans a point that lie in the same plane

The radius of the circle is 4 cm and the measure of the central angle is 90° the area of the sector with a central angle measuring 90° and radius of length 4 cm is vt cm the triangle in the sector is 4 cm the area of the triangle is v/cm² the area of the segment of the circle is (471 - ) cm?