If the whole angle (ABC) is equal to 133, we can add angles ABD and DBC to find x.
10x+13=133 Subtract 13 from both sides to get 10x=120 Divide both sides by 10 to get that x=12
We can now plug the value of x into ABD to find its measure. 7(12)+4 Simplifies to 84+4, which is 88
So angle ABD is equal to 88 degrees.
:)
answered: Guest
according to the triangle sum theorem, all the angles in a triangle must add up to 180 degrees. if we know one angle is already 90, we do 180-90=90. the other 2 angles must add up to 90, exactly.