Question

I don’t understand this problem please please help

Answer 1

m ∠C = 65°

m ∠D = 25°

Explanation:

• the sum of interior angles of a triangle is 180°

angle D and 155° make a straight angle

• a straight angle is 180°

that's mean you can measure angle D

the measure of angle D is :

180 (straight angle) - 155 = 25

so D is 25°

now you have the measure of two angles

1. 90° or quadrant angle
2. 25° or ∠D

you can measure the third angle

remember the sum of interior angles of a triangle is 180°

a triangle has three angle

so to find the measure of third angle = the sum of all angles - the sum of two angles

180 - (90 + 25) = 65

the measure of angle D is 65°

well you have the measure of all angles

1. 90° or quadrant angle
2. 25° or ∠D
3. 65° or ∠C

m ∠C = 65°

m ∠D = 25°