a.nilai x b.luas ...............

x = √(10²/2)
= √(100/2)
= √50
= √25.2
= 5√2 cm

luas = x²
= (5√2)²
= 50 cm²

a.nilai x
x²+x²=10²
2x²=100
x²=100/2
x²=50
x=√50

b.luas
√50×√50
√2.500
=50 cm²

jadi , luas =50 cm²