Explanation:
you don't know the Pythagoras formula yet ?
this is something you need to remember for life. this you will encounter everywhere (not just in school) :
c² = a² + b²
in a right-angled triangle c is the Hypotenuse (the side opposite of the 90° angle). a and b are the legs of the triangle.
4.
the legs of this right-angled triangle are the pole and the ground distance to the cable fixture on the ground.
the cable itself is the Hypotenuse (as the right angle is the angle between the pole and the ground distance).
so,
cable² = 8² + 6² = 64 + 36 = 100
cable = sqrt(100) = 10 m
5.
here we have a right-angled triangle with the direct distance between the points being the Hypotenuse, and the x and y coordinate differences are the legs.
so, we have
distance² = (3 - -3)² + (0 - -1)² = 6² + 1² = 36 + 1 = 37
distance = sqrt(37)
please note that since we are squaring, the direction of the differences and their signs do not matter. the square will turn positive and negative distances into positive numbers.