Question

Determine m angle F by using the figure

Answer 1

The measure of angle F is m∠F=130°

Explanation:

step 1

Find the measure of angle E

we know that

An isosceles triangle has two equal sides and two equal interior angles

In this problem

DF=EF ----> given problem

so

Triangle DEF is an isosceles triangle

m∠D=m∠E

we have

m∠D=25°

substitute

m∠E=25°

step 2

Find the measure of angle F

we know that

The sum of the measures of the interior angles in a triangle must be equal to 180 degrees

so

m∠D+m∠E+m∠F=180°

substitute the values

25°+25°+m∠F=180°

50°+m∠F=180°

m∠F=180°-50°

m∠F=130°