To find 50 percent, you multiply the number by 0.5 (for 30%, 0.3 etc.).
42.88 * 0.5 = 21.44
2.40
5.40-2.40= 3 (price of 2 sodas)
8.70 - 7.20 = 1.5 (price of 1 soda)
The soda prices match up so a hamburger is 2.40
⇒ s = a+b+c2=5+12+132 a + b + c 2 = 5 + 12 + 13 2 = 15 cm.
Area of the base = √s(s−a)(s−b)(s−c)
= √15×10×3×2 15 × 10 × 3 × 2 cm2 = 30 cm2
