Question

Using the figure given below, find the value of x. (Assume all values are given in degrees)

• A. ${17}^{\circ }$
• B. ${10}^{\circ }$
• C. ${50}^{\circ }$
• D. $5^{\circ }$

Answer 1

The correct option is B ${10}^{\circ }$

Since the lines given in the figure are parallel lines being cut by a transversal, x and 3x-20 are forming Exterior Alternate angles.
Exterior Altenate angles are equal in measure. .

Therefore,
x= 3x-20
3x - x= 20
2x = 20
x = 10
Hence x = ${10}^{\circ }$