Rule needed: i^2 = -1
Standard form a + bi
(3 + 2i)(7 - 5i) FOIL
3 * 7 = 21
3 * - 5i = - 15i
2i * 7 = 14i
2i * -5i = - 10i^2 = - 10 * -1 = 10
Putting it all back together.
31 - i
Hi my name is bob plz give brainpower
Area of the triangle = (1/2)*base* height = (1/2)*3*6 = 9 sm²
We have 4 triangles like this one ,
so area of 4 triangles = 9*4 = 36 cm².
Area of the square = 3*3 = 9 cm²
Surface area here means area all triangles + area of the square =36 +9 =
= 45 cm ²
Answer is 45 cm².