Can some one help me what is this math called it looks like this and these are two separate problems.

Which measurement is the most precise? a) 29 cm b) 28.8 cm eliminate c) 28.76 cm d) 28.762 cm

Maci and i are making a small kite. two sides are 10". two sides are 5". the shorter diagonal is 6". round all your answers to the nearest tenth. 1. what is the distance from the peak of the kite to the intersection of the diagonals? 2. what is the distance from intersection of the diagonals to the top of the tail? 3. what is the length of the longer diagonal?

Given right triangle a w/a hypotenuse length of x+4 and a leg of x, and right triangle b, w/ a hypotense length of 3y and a leg length of y+4 for what values of x and y are the triangles congruent by hl?