A car travels 21 km in 16 minutes. What is its average speed in km/h? Give your answer rounded to 1 decimal place.

78.6km/h

Step-by-step explanation:

Speed=distance÷time

distance=21km

time=16 minutes(convert into hour by dividing it with 60)

=16÷60=0.267

Speed=21÷0.267=78.65km/h

first, you divide the triangle in two, tô form a retangle triangle. after, using pythagoream theorem:

18^2 = 14^2 + (x/2)^2

(x^2/4) + 196 = 324

x^2/4 = 324 - 196

x^2/4 = 128

x^2 = 512

x = √512

x = √2^9

x = 16√2 cm

i hope i you.