area of a trapezoid free area is a designated Calculate the area of a trapezoid using its bases and height with this online tool. Learn the formula, see an example and cite the source of this calculator
area of a triangle To calculate the area of a triangle, start by measuring 1 side of the triangle to get the triangle's base. Then, measure the height of the triangle by measuring from the center of the base to the point directly across from it
area of a circle To find the area using the diameter d, we modify our formula to A = πd/2². This is really the same formula, just adjusted for diameter. Let me walk through how to convert the area formula from radius to diameter. We begin with our familiar formula for the area of a circle using radius: A = πr². We know that diameter d is twice the
