Abuilding is in the shape of a square pyramid. each side of the base is 54 meters long and the height is 260 meters. what is the volume of the building? enter your answer in the box. m³

Ametalworker has a metal alloy that is 30? % copper and another alloy that is 55? % copper. how many kilograms of each alloy should the metalworker combine to create 90 kg of a 50? % copper? alloy?

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?