Question

Someone help me with number 3

Answer 1

Angle ABD = 40 Degrees. Angle DBC = 50 Degrees. Because we know that a right angle ( a boxed corner ) is 90 Degrees, you add up the X's and divide by 90 to find what X is. X in this case is 10. You then multiply using X ( 10 ). 4x10 is 40 and 5x10 is 50. Thus getting your angles.

Answer 2

The angle ABC is 90 degrees.
It is divided into two angles.

One is 4x, and one is 5x. Together that is 9x.
9x = 90
Divide each side by 9 to get x.
x = 10

Multiply 4 by 10 to get 40 for angle ABD.
Multiply 5 by 10 to get 50 for angle DBC.

∠ABD is 40º.
∠DBC is 50º.

Hope this helps!