Find the measure of the angle and explain step by step

angle 4 is the same as angle 8

 angle 7 & angle 8 has to equal 180 degree

 so angle 7 and angle 4 also have to equal 180

angle 4 is 3 times the size of 7

lets call 7  (x)

so 4(x) = 180

180/4  =45

x=45

angle 7 is 45 degrees

25 questions , because they start with 100.  

350-100=250 .  

. 250/10=25

step-by-step explanation:

first take off 100, then what x 10 = 250? that is your answer. (25)

proofs involving isosceles triangles often require special consideration because an isosceles triangle has several distinct properties that do not apply to normal triangles.(more about triangle types) therefore, when you are trying to prove that two triangles are congruent, and one or both triangles, are isosceles you have a few theorems that you can use to make your life easier.

step-by-step explanation:

an isosceles triangle has two congruent sides and two congruent angles. the congruent angles are called the base angles and the other angle is known as the vertex angle. ∠bac and ∠bca are the base angles of the triangle picture on the left. the vertex angle is ∠abc