Ineed to know the surface area. the formula is area of base + area of lateral faces
i will mark you brainliest

215.1 yd²

Step-by-step explanation:

We have three triangles with base b = 9yd and height h = 10yd, and one triangle in the base of pyramid with base b = 9yd and height h = 7.8yd.

The formula of an area of a triangle:

Substitute:

Answer: the correct answer is 10step-by-step explanation: let the number be n, then the expression becomes,then“twelve more than the quotient of a number and two, decreased by four” iswhen n=4,we substitute 4 whetever we see n to get,we simplify to obtain,we further simplify to get,therefore the correct answer is c.