Tolong bantuanya,,,,,,,

Tolong bantuanya,,,,,,,

$a = 10 div 2 = 5 \ h = sqrt{ {a}^{2} + {t}^{2}} = sqrt{ {5}^{2} + {12}^{2} } \ sqrt{25 + 144} = sqrt{169} = 13 \ \ lp : prisma : segitiga \ (as times ts) + ((as + h+ h) times tp) \ (10 times 12) + ((10 + 13 + 13) times20) \ 120 + (36 times 20) \120 + 720 \840 : {cm}^{2}$