Answer:
b = 87°
Step-by-step explanation:
In order to answer this question, we need to utilise an important angle fact which is angles in a quadrilateral add up to 360°
Using the information we can set up an equation to find the value of b
→ Form equation
63 + 140 + 70 + b = 360
→ Simplify
273 + b = 360
→ Minus 273 from both sides isolate b
b = 87°
