Geometry help needed ?

Question

In triangle ABC, angle C is a right angle. Find the measure of angle B if side b = 105 m and side c = 139 m.

Answer 1

just use the cosine law.,which is c^2=a^2+b^2-2abcosC.,get first side a then use the law.,but i'm not sure about it.,cause its a ryt triangle.,

ther's also another law.,its the sine law.,which is.,a over sinA is equal to b over sinB is equal to c over sinC.,not sure also.,en i don't think if these 2 will apply on right triangles.,

its one of our past lessons in trigonometry.,i forgot about our past lessons in geometry last2 school year..,

Answer 2

Start by drawing a diagram of a right angled triangle, label it correctly.

now use the sin rule , sinA/a = sinB/b = sinC/c.

we substitute in the values that we know

                sinB/105 = sin90/139

we are trying to find the value of B , so we try to make it the subject of the equation.

                multiply both sides by 105

                sinB = 105sin90/139

                since sin90 = 1, we have sinB = 105/139

the inverse function os sin will then tell us that B = 49.05

Answer 3

Oh, geez, wish I would have paid attention in math class

I still don't know how to do these