To find the distance AB across a river, a distance BC of 415 m is laid off on one side of the river. It is found that B = 112.2° and C = 18.3°. Find AB.

91.87

Step-by-step explanation:

We are given that BC=361m, Angle B= ° degrees,     1 degrees = 60 minutes, Angle C= 12 °  15' = 12 + = 12.25 degrees, We have to find the value of AB, the Sum of angles of triangle=180 degrees, ⦟A + ⦟B + ⦟C = 180 degrees, ⦟A=180- ( ⦟C+ ⦟B)= 180 - (111.33 + 12.25)=56.42 degrees, By using law of sine, = , AB= =, AB= 91.87