A10 meter ladder is inclined against a wall at an angle of elevation of 20°. if the top of the ladder reaches the top of the wall, how tall is the wall?

Wall's height = 3.42 m

Explanation:

Length of the ladder = 10 meter

Suppose height of the wall = h meter

"Please find the attached image"

One right angle triangle whose opposite side is h and hypotenuse is 10m

We use the trigonometric ratio

sin Θ =

sin Θ =

sin(20) =

0.3420 =

Solve for h

h = 0.3420 * 10

h = 3.42 m

Height of the wall is 3.42 m

- "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."