Answer:
Kindly check attached picture 
Quantity measured is DISTANCE
Step-by-step explanation:
Segment AB = measures uniform deceleration 
BC = Constant speed moved by the car
CD = Uniform acceleration 
During uniform deceleration: the speed of the body is reduced at a constant rate with time. 
During Constant Speed, the car maintains a Velocity which does not increase or reduce at a certain time interval. 
During uniform acceleration the speed of the car increases at a constant rate with time. 
B) THE quantity measured by the area covered under a speed-time graph is distance :
With speed on the vertical (y-axis) and time on the horizontal (x-axis) 
Area of trapezium = 0.5(AD + BC) × height