Find the value of x in each case:

x = 17

Step-by-step explanation:

The sum of the angles in a triangle = 180°, thus

∠ECD = 180 - (100 + x) = 180 - 100 - x = 80 - x

∠ACB = 180 - (49 + 4x) = 180 - 49 - 4x = 131 - 4x

∠ECD = ∠ACB ( vertical angles are congruent ), that ia

80 - x = 131 - 4x ( add 4x to both sides )

80 + 3x = 131 ( subtract 80 from both sides )

3x = 51 ( divide both sides by 3 )

x = 17

the answer for this question is : 360°

step-by-step explanation:

we have been given a triangle   we need to tell which one of these is a triangle below to map onto itself.

360° rotation is the complete rotation which eventually leads to the same figure which is given.

the correct will be, that is 360° that will cause the triangle below to map onto itself.