11 Plus Exams Forum

How do you find the missing side length of a right angle triangle when only one length(the longest length) is known? In this case 10cm
The 2 unknown sides are of equal length.

Any help would be gratefully appreciated

OK - so Pythagoras says @the square on the hypotenuse = sum of the squares on the other two sides"

So 10^2 = the other two sides .... but we know they are equal so each 'square' must be ....?

I'm clearly being really stupid here so apologies in advance.
I'm trying to help DD but she's in the shower at the moment.
The answer in the book states the missing sides are 7.07 but I can't get to this at all. Dd is getting 3.16

So 10 ^ 2 = 100 so two equal things squared = 100. What will each be?

How do you then find the length of a side from this?

Thank you for your help, Dd is still struggling so she's going to go to maths club at school tomorrow

Call the unknown side a

Then a^2 + a^2 = 10^2 = 100

So a^2 = ...

a =

[ Off out in a minute so rushing]