Find the area of the shaded figure

An angel appears at a faculty meeting and tells the dean that in return for his unselfish and exemplary behavior, the Lord will reward him with his choice of infinite wealth, wisdom, or beauty.

Without hesitating, the dean selects infinite wisdom.

"Done!" says the angel, and disappears in a cloud of smoke and a bolt of lightning.

Now, all heads turn toward the dean, who sits surrounded by a faint halo of light.

One of his colleagues whispers, "Say something."

The dean sighs and says, "I should have taken the money."