Find the lateral area and surface area of a regular pyramid.

The lateral surface area is comprised of 4 equal triangles......each with a base of 9 yds. and a heightt of 10 yds.

So....the total lateral surface  area =  4 [b*h]/2  = 2 b * h =  2 [ 9 yds] * [ 10 yds]  =  180 sq yds.