Jawabanmu

2014-05-21T20:02:22+07:00
a.) a = 7, b = 24 , c = √24²+7² = √576+49 = √625 = 25
Lp = (2La) + (Ka.t) = (2 x 7 x 24/2) + ((7+24+25) 20) = (336/2) + 1120 = 168 + 1120 = 1288 cm²
b.) 
V = La.t = 7 x 24/2 x 20 = 168/2 x 20 = 168 x 10 = 1680 cm³
2014-05-21T20:03:49+07:00
A.  LP = 2× (a×t÷2) + (p×l) + (p×l) + (p×l)
     LP = 2× (24 × 7 ÷2) + (24×20) + (25 × 20) + (7×20)
     LP = 168 + 480 + 500 + 140
     LP =1288  cm²
b.  V = (L. alas segitiga) × T
     V = (24 × 7 ÷ 2) × 20
     V = (12 × 7) × 20
     V = 84 × 20
     V = 1680 cm³