Ayuda necesito esto rapido

Which expression gives the area of the triangle shown below

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

If the speed of an electromagnetic wave is 100,000 cm/s and its wavelength is 100 cm, what is its frequency? a) 100,000 cycles per second (hz) b) 1 × 10-3 cycles per second (hz) c) 10,000,000 cycles per second (hz) d) 1,000 cycles per second (hz)