<prompt> Je! ni eneo gani, katika vitengo vya mraba, la pembetatu ya kulia ya isosceles na hypotenuse ya vitengo 20?  <response>: Kila mguu wa pembetatu 45-45-90 na hypotenuse ya vitengo 20 hupima frac20sqrt2 units. Eneo ni frac12textbasetextheightfrac12leftfrac20sqrt2 kulialeftfrac20sqrt2rightfrac4002cdot 2100text square units. 