How to solve and write a linear equation ?

The diagram shows a 7cm by 6cm rectangle based pyramid. all the diagonal sides - ta, tb, tc and td are length 10cm. m is midpoint of rectangular base. work out height mt to 1 decimal place

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?

Show your workcan a right triangle have this sides? *how to prove it without using the pythagorean theorema*