1. [tex]1. \: parallelogram - \: \: a = \: b \times h \\ 2. \: triangles - \: \: a = \frac{1}{2} b \times h \\ 3. \: trapazoid - \: \: \frac{1}{2} (base1 + base2) \times h \\ 4. \: circles - \: \: \pi {r}^{2} [/tex] 2. is the last option. 3. is d 4. is a