We are given the height so we need to find the length of the sides. Since this is an equilateral triangle, the triangles formed by height will be special triangles with 30, 60 and 90 angles. Then if we call the side length a, the side across from 30 degrees will be a/2 units long.

Get an answer for 'The altitude of an equilateral triangle is 9 meters, what is the side length' and find homework help for other Math questions at eNotes A tetrahedron is a three-dimensional figure with four equilateral triangles. If you lift up three triangles (1), you get the tetrahedron in top view (2). Generally it is shown in perspective (3). If you look at the word tetrahedron (tetrahedron means "with four planes"), you could call every pyramid with a triangle as the base a tetrahedron.

To find the area of a trapezoid, take the sum of its bases, multiply the sum by the height of the trapezoid, and then divide the result by 2, The formula for the area of a trapezoid is: or Where is , is , is height and · means multiply. Each base of a trapezoid must be perpendicular to the height. In the diagram above, both bases are sides of ... Jul 01, 2008 · in an equilateral triangle, all of its sides are equal, its perimeter is the addition of all three sides.. so if perimeter = 21 the a + b + c = 21, since they are equal a = b = c = 21/3 = 7.. The area formula is Base*height/2 = bh/2. To find the height you will need to divide your triangle in half and use the Pythagorean theorem to find it.

The perimeter of the isosceles triangle is relatively simple to calculate, as shown below. ${\text{perimeter}} = 2a + b$ Also note that the area of the isosceles triangle can be calculated using Heron’s formula. The Distance Formula . Example Find the distance between (1, 4) and (-2, 3). ... •What is the length of the altitude of an equilateral triangle if a side is 12 cm?