Determine Angle GDC: Complex Figure with 90° and 95° Known Angles

Question

It is known that angles A and D are equal to 90 degrees

Angle DEB is equal to 95 degrees

Complete the value of angle GDC based on the data from the figure.

505050404040707070AAABBBCCCDDDEEEFFFGGG3025

Video Solution

Solution Steps

00:00 Find angle GDC
00:11 The entire angle equals the sum of its parts
00:36 We'll substitute appropriate values according to the given data and solve for the angle
00:53 We'll isolate angle GDC
01:03 And this is the solution to the question

Step-by-Step Solution

Note that the GDC angle is part of the EDC angle.

Therefore, we can write the following expression:

GDC+EDG=EDC GDC+EDG=EDC

Since we know that angle D equals 90 degrees, we will substitute the values in the formula:

GDC+40=90 GDC+40=90

We will simplify the expression and keep the appropriate sign:

GDC=9040 GDC=90-40

GDC=50 GDC=50

Answer

50