Respuesta :
Step-by-step explanation:
a. Pythagoras formula stated above
so 9²+12²
81+144 is 225
√252 is 15cm
b. in this question well have to use surds
an isosceles triangle had a 90 and 2x45 degree angles
we hypotenuse is 10cm
√a²+a² =10cm
√2a² is 10cm which makes
a√2 equals 10
then rearrange
a=10/√2= 5√2
the answer is 5√2