Question

find the sizes of unknown angles.​

Answer 1

Answer:

40 degree

Step-by-step explanation:

$join \: ob \: \\ now \: angle \: oab = angle \: oba \: angle \: ocb = angle \: obc \: \\ \\ beacuse \: sides \: are \: equal \: radius \\ \\ angle \: abc \: = 40 + 30 = 70 \: and \: angle \: aoc = 2angle \: abc \: = 2 \times 70 \\ \\ 140 \: degree \: \: quad \: aocd \: \\ \\ \\ angle \: aoc \: + angle \: adc \: \\ 140 + \: angle \: adc \: = 180 \\ \\ \\ x = 180 - 140 = 40$