ABC congruent DEF find the measure of the given angles or the lengths of the given sides

Answer:
m∠A = 20° and m∠D = 20°
Step-by-step explanation:
Congruent triangles have equal angles, equal sides, equal perimeters, and equal areas
Let us solve the question
∵ The two triangles ABC and DEF are congruent
∴ m∠A = m∠D
∵ m∠A = x + 10
∵ m∠D = 2x
→ Equate their measures
∴ 2x = x + 10
→ Subtract x from both sides
∵ 2x - x = x - x + 10
∴ x = 10
→ Substitute x by 10 in the measures of angles A and D to find them
∵ m∠A = 10 + 10
∴ m∠A = 20°
∵ m∠D = 2(10)
∴ m∠D = 20°