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From the given figure, find the length of hypotenuse AC and the perimeter of ∆ABC.

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#### Solution

Given here is a right-angled triangle. So, we can apply Pythagoras theorem.

AB^{2} + BC^{2} = AC^{2}

⇒ 20^{2} + 21^{2} = AC^{2}

⇒ AC^{2} = 400 + 441 = 841

⇒ AC = 29

Thus, the length of hypotenuse is 29 units.

Perimeter of ∆ABC = AB + BC + CA = 20 + 21 + 29 = 70 units.

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