Question

Please help I am confused.

Answer 1

x = 87

Add all of the known measurements in the triangle then subtract it from 180. The difference is the value of x. To find the measure of D, a straight line is equal to 180 so subtract 180 from 42 degrees.

51 + 42 = 93

180 - 93 = 87

180 - 42 = 138

m<D = 138

Answer 2

Here,

X°+ 51°+42°=180°( being sum of three angle of a triangle)

or, X°+93°=180°

or, X°=180°-93°

.°. X°= 87° ans.

Now,

<D + 42°=180°( being angle in a straightline)

or, <D=180°- 42°

.°. <D= 138° ans.

Hope this helps you!