When wiring a house, an electrician knows that the time she by the Time = 2 hours + 12 minutes per lightswitch She charges her customers a call-out fee of £35, plus £30 per hour. How much should a customer be charged for wiring a house with 10 lightswitches?

3,4,5 ; 5,12,13 ; 9,12,15 are the possible measures of the triangle's sides.

Step-by-step explanation:

Let us consider a triangle having three sides,

For a normal triangle all the three sides will be equal , but as the given values are not equal it should be a right angle triangle.

The area of right angle triangle is given by pythagoras theorem.

(Area of 1st side)² + (Area of 2nd side)² = (Area of 3rd side)²

Now as we have given different values we have to choose which series suits a triangle

i.) 3,4,5

By applying theorem,

1st side² + 2nd side² = 3rd side²

3² + 4² = 5²

9 + 16 = 25

25=25

ii.) 5, 12, 13

similarly as above

5² + 12² = 13²

169 = 169

iii.)9, 12 ,15

9² + 12² = 15²

81 + 144 = 225

225 = 225

Therefore these are the values of series which best suits and forms right angled triangle.