Suppose a triangle has two sides of length 42 and 35, and that the angle between these two sides is 120°. Which equation should you solve to find the
length of the third side of the triangle?

you should use cosine law

it state that the third side lets name it c

c^2=a^2+b^2 -2 × a × b × cos (angle between the 2 sides)

a and b are the 2 sides given

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it

it shoild be o

step-by-step explanation: