Is 87,000 square feet as big as Washington National Cathedral?
It's about one-thirtieth as big as Washington National Cathedral

The size of Washington National Cathedral is about 2,500,000 square feet.
(a.k.a. Cathedral Church of Saint Peter and Saint Paul) (Washington, DC) (total plot)
Sitting atop the 115 m (377 ft) tall Mount Saint Alban at the corner of Massachusetts and Wisconsin Avenues, Washington National Cathedral sits on a landscaped, 2,500,000 square feet plot.
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