57+23 = 80
not rounded it's 80.14
He can either measure the third side length, apply the Pythagorean theorem to find the height of the triangle, and then calculate the area, or he can find the measure of the included angle between the known side lengths and use trigonometry to express the height of the triangle and then determine the
area of the triangle
Idk what you mean the answer is 15 students eat six pizzas
You need to measure the angles wich means that u use a protractor if the angle is 90 degrees is a straight angle if it is below 90 degrees is acute and if it is above 90 degrees it's obtuse