Triangles © T Madas
? ? Isosceles Equilateral Scalene Acute Does not exist Obtuse Right angled Does not exist © T Madas
The angles in a triangle add up to 180 degrees © T Madas
The angles in a triangle add up to 180° © T Madas
The angles in a triangle add up to 180° © T Madas
The angles in a triangle add up to 180° © T Madas
Practice Angle Calculations with Triangles © T Madas
Calculations with Triangles 60° 100° 45° 45° 35° 70° 50° 80° 55° 45° 65° 25° 65° 70° 25° 30° 55° 120° 115° 35° 35° 75° 50° © T Madas
Calculations with Triangles 70° 104° 48° 43° 33° 65° 45° 80° 52° 47° 61° 29° 62° 71° 24° 33° 52° 117° 109° 39° 38° 77° 51° © T Madas
Calculations with Triangles 80° 101° 47° 43° 36° 60° 40° 80° 53° 48° 64° 26° 61° 71° 23° 32° 52° 117° 110° 40° 38° 78° 50° © T Madas
Calculations with Isosceles Triangles 50° 40° 70° 40° 100° 55° 55° 70° 70° 65° 65° 40° 80° 110° 45° 45° 20° 80° 35° 35° © T Madas
Quick Test on Angle Calculations with Triangles © T Madas
Calculations with Triangles 60° 100° 45° 45° 35° 70° 50° 80° 55° 45° 65° 25° 65° 70° 25° 30° 55° 120° 115° 35° 35° 75° 50° © T Madas
Calculations with Triangles 70° 104° 48° 43° 33° 65° 45° 80° 52° 47° 61° 29° 62° 71° 24° 33° 52° 117° 109° 39° 38° 77° 51° © T Madas
Calculations with Triangles 80° 101° 47° 43° 36° 60° 40° 80° 53° 48° 64° 26° 61° 71° 23° 32° 52° 117° 110° 40° 38° 78° 50° © T Madas
Calculations with Isosceles Triangles 50° 40° 70° 40° 100° 55° 55° 70° 70° 65° 65° 40° 80° 110° 45° 45° 20° 80° 35° 35° © T Madas
© T Madas
An isosceles triangle ABC is drawn below, with the points A and B fixed and point C free to move. Mark on the grid another position for point C, so that triangle is still isosceles. 0 1 2 3 4 5 6 6 5 4 3 2 1 C A B © T Madas
An isosceles triangle ABC is drawn below, with the points A and B fixed and point C free to move. Mark on the grid another position for point C, so that triangle is still isosceles. 0 1 2 3 4 5 6 6 5 4 3 2 1 C A B © T Madas
An isosceles triangle ABC is drawn below, with the points A and B fixed and point C free to move. Mark on the grid another position for point C, so that triangle is still isosceles. 0 1 2 3 4 5 6 6 5 4 3 2 1 A B © T Madas
An isosceles triangle ABC is drawn below, with the points A and B fixed and point C free to move. Mark on the grid another position for point C, so that triangle is still isosceles. 0 1 2 3 4 5 6 6 5 4 3 2 1 C A B © T Madas
An isosceles triangle ABC is drawn below, with the points A and B fixed and point C free to move. Mark on the grid another position for point C, so that triangle is still isosceles. 0 1 2 3 4 5 6 6 5 4 3 2 1 C A B © T Madas
An isosceles triangle ABC is drawn below, with the points A and B fixed and point C free to move. Mark on the grid another position for point C, so that triangle is still isosceles. 0 1 2 3 4 5 6 6 5 4 3 2 1 C A B Mark on the grid another position for point C, so that triangle is isosceles and right angled. © T Madas
An isosceles triangle ABC is drawn below, with the points A and B fixed and point C free to move. Mark on the grid another position for point C, so that triangle is still isosceles. 0 1 2 3 4 5 6 6 5 4 3 2 1 C A B Mark on the grid another position for point C, so that triangle is isosceles and right angled. © T Madas
© T Madas
Calculate the angle marked as x. 69° 61° 21° 29° 50° x © T Madas
© T Madas
Calculate the angle marked as x 20° 50° 130° 70° 30° x © T Madas
© T Madas
Calculate the angle marked as x. 49° 41° 49° x © T Madas
© T Madas
Calculate the three angles of the triangle 70° 140° 40° 70° Calculate the angle marked with x 55° 110° x 70° 55° © T Madas
© T Madas
Calculate the angle marked with x 292° x 68° 136° 44° 68° © T Madas
© T Madas
Calculate the missing angles in each triangle 70° 50° 55° 55° 65° 65° © T Madas
© T Madas
One of the angles of an isosceles triangle is 64°. What are the sizes of the other two angles? [You must show that there are 2 different possibilities] 1st possibility 2nd possibility 52° 64° 64° 64° 58° 58° 64 + 64 128 180 – 128 52 180 – 64 116 116 ÷ 2 = 58° © T Madas
© T Madas