Current location - Training Enrollment Network - Mathematics courses - 20 10 how to do the seventh multiple-choice question in mathematics for the senior high school entrance examination in Texas? What geometry is this?
20 10 how to do the seventh multiple-choice question in mathematics for the senior high school entrance examination in Texas? What geometry is this?
Because: this geometry is a cone with isosceles triangles, and the center area of the triangle = 1/2 times the height.
So excluding C and D, the original diameter of the top view is a= the bottom of the triangle on the side (front view and left view).
And it is already known that the height is b, so according to the area formula: a.