1. If AC and BD are the diagonals of a parallelogram ABCD show that AC? +BD = 2(AB + AD'). b AC?-BD = 4 AB - AD. by vector method:​

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

include a picture of the drawing in order for me to

step-by-step explanation:

no idea

step-by-step explanation: