Question

Find an obtuse angle whose sine is
a) 0.25
b) 0.75
c) 0.875
d) 0.3465

Answer 1

a) 165.52 degrees.

b) 131.41 degrees.

c) 118.96 degrees.

d) 159.73 degrees.

Explanation:

The sine of an obtuse angle is positive as it is in the second quadrant.

a) Using a calculate the angle whose sine ( arcsin) is 0.25 = 14.478 degrees

so the obtuse angle = 180 - 14.478 = 165.52 degrees to nearest hundredth

b) c) and d) are calculated in the same way.