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In figure, ∠AOB = 90°, AC = BC, OA = 12 cm and OC = 6.5 cm. Find the area of ΔAOB. |
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Answer» Given: A triangle AOB, with ∠AOB = 90o, AC = BC, OA = 12 cm and OC = 6.5 cm As we know, the midpoint of the hypotenuse of a right triangle is equidistant from the vertices. So, CB = CA = OC = 6.5 cm AB = 2 CB = 2 x 6.5 cm = 13 cm In right ΔOAB: Using Pythagorean Theorem, we get AB2 = OB2 + OA2 132 = OB2 + 122 OB2 = 169 – 144 = 25 or OB = 5 cm Now, Area of ΔAOB = 1/2(Base x height) cm2 = 1/2(12 x 5) cm2 = 30 cm2 |
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