Question

EF=DE;∢DEF=47°. Угол D равен

Answer 1

Ответ:66,5

Объяснение:

Так как две стороны в треугольнике равны, то он является равнобедренным, значит углы при основании равны

Угол D = углу F

Сумма всех углов треугольника = 180 градусов.

Значит угол D + угол F = 180 - угол Е= 180-47=133.

Угол D = 133:2=66,5

Answer 2

To find the measure of angle D, we can use the fact that the sum of the angles in a triangle is always 180 degrees.

Let's assume that angle D is x degrees.

In triangle DEF, we know that EF = DE, and ∢DEF = 47°.

Now, the sum of the angles in triangle DEF is:

∢D + ∢E + ∢F = 180°

Substituting the given information:

x + ∢E + 47° = 180°

Now, we need to find the measure of angle E. Since EF = DE, it means that angles E and F are congruent (they have the same measure).

So, ∢E = ∢F

Now, let's rewrite the equation with this information:

x + ∢F + 47° = 180°

Since ∢F = ∢E, we can write:

x + ∢E + 47° = 180°

Now, the sum of the angles in triangle DEF is still 180 degrees, so we can write:

47° + 47° + x = 180°

Solving for x:

94° + x = 180°

Subtract 94° from both sides:

x = 180° - 94°

x = 86°

So, the measure of angle D (∢D) is 86 degrees.