Congruent triangles Congruent triangles are triangles that have the same size and shape. Congruent triangles are triangles that have the same size and shape. Congruent triangles Similar triangles are triangles that have the same size and shape. Congruent triangles Similar triangles are triangles that have the same size and shape. Congruent triangles Similar triangles have the same shape but different sizes. Congruent ? Similar ? How do we know when triangles are similar? How do we know when triangles are similar? 2 5 4 1 2.5 2 How do we know when triangles are similar? Their corresponding angles have to be exactly the same. 2 5 4 1 2.5 2 How do we know when triangles are similar? Their corresponding angles have to be the same. 2 5 4 1 2.5 2 This symbol means the angles have the same value. How do we know when triangles are similar? Their corresponding angles must have the same values. 2 5 4 1 2.5 2 These angles are the same. How do we know when triangles are similar? Their corresponding angles must have the same value. 2 5 4 1 2.5 2 These angles are the same. Their corresponding sides have to be proportional. How do we know when triangles are similar? Their corresponding angles must have the same values. 2 5 4 1 2.5 2 Their corresponding sides have to be proportional. How do we know when triangles are similar? Their corresponding angles must have the same values. (Proportional means they have to divide to the same thing.) 2 5 4 1 2.5 2 Their corresponding sides have to be proportional. How do we know when triangles are similar? Their corresponding angles must have the same value. 2 5 4 1 2.5 2 4 ÷ 2 = 2 Their corresponding sides have to be proportional. How do we know when triangles are similar? Their corresponding angles must have the same value. 2 5 4 1 2.5 2 4 ÷ 2 = 2 2 ÷ 1 = 2 Their corresponding sides have to be proportional. How do we know when triangles are similar? Their corresponding angles must have the same values. 2 5 4 1 2.5 2 4 ÷ 2 = 2 2 ÷ 1 = 2 5 ÷ 2.5 = 2 Their corresponding sides have to be proportional. How do we know when triangles are similar? Their corresponding angles must have the same values. 2 5 4 1 2.5 2 4 ÷ 2 = 2 2 ÷ 1 = 2 5 ÷ 2.5 = 2 Their corresponding sides have to be proportional. How do we know when triangles are similar? Their corresponding angles must have the same values. 2 5 4 1 2.5 2 4 ÷ 2 = 2 2 ÷ 1 = 2 5 ÷ 2.5 = 2 All the same For shapes to be similar their corresponding angles must be their corresponding sides must be proportional ? the same ? We can use similarity We can use similarity to find unknown sides We can use similarity to find unknown sides 2 5 x 10 We can use similarity to find unknown sides 2 5 x 10 corresponding sides These are We can use similarity to find unknown sides 2 5 x 10 corresponding sides These are We can use similarity to find unknown sides 2 5 x 10 2 x = 10 5 We can use similarity to find unknown sides 2 5 x 10 Solve 2 x = 10 5 We can use similarity to find unknown sides 2 5 x 10 Solve 2 x 5x = 20 = 10 5 We can use similarity to find unknown sides 2 5 x 10 Solve 2 x 5x = 20 x = 4 = 10 5 x x = 5 8 10 |