Answer:
Step-by-step explanation:
This question involves the concept of similar triangles.
The pair of triangles that are similar are "B and D".
A pair of triangles is termed as similar triangles if the two angles of both the triangles are equal to each other. Hence, we will check this condition for each pair given in the question.
A.
Only one angle is given to be equal for both the triangles, while the other two angles are unknown. Hence, this pair can not be termed as similar.
B.
For an isoceles triangle, two sides and two angles of the triangle are equal. Considering the 40° angle to be the equal angle, we can safely conclude that the two angles of both the triangles in the pair are the same. Hence, this pair can be termed as similar.
C.
Triangle 5 has angles: 30°, 90° and (180°-30°-90°) = 60°. While triangle 6 has angles: 30°, 70°, and (180°-70°-30°) = 80°. Since all the angles of both the triangles are different. Therefore, they can not be termed as similar.
D.
Triangle 7 has angles: 50°, 20° and (180°-50°-25°) = 105°. While triangle 6 has angles: 50°, 105°, and (180°-50°-105°) = 25°. Since all the angles of both the triangles are equal. Therefore, they can be termed as similar.
