How to find missing angles in right triangles

Show that the sum, over the set of people at a party, of the number of people a person has shaken hands with, is even. assume that no one shake his or her own hand.

Given the equation y=-2x^2+1. determine the direction of opening, coordinates of the vertex, Maximum or minimum value and the axis of symmetry

The diameter of a circle is 8 kilometers. What is the angle measure of an arc kilometers long?

Driveway pavers are 6 inches by 9 inches. If your driveway is 20142 square inches, how many pavers do you need for your driveway?

The perimeter of a square is 36 what is the area of the square?

Find the sum of the interior angles and the number of diagonals of a regular polygon whose central angle is 6

X - y = 4 2x + y = 5 Elimination method

A number is between 1 and 5 what is the least integer value of its opposite

Y=3x-4 Y-1/2x+3 Find coordinates and explain

a company has has 95000 shares of stock to sell a stockbroker decides to buy 150 shirts of the stock for each of the 250 clients how many shares will the company have left to sell after the stock broker makes her purchase