Let's solve the problem step by step. ### **Given:** - **Brick type:** Modular brick - **Mortar joint thickness:** 3/8" - **Opening:** 6-1/2 bricks wide, 29 courses high ### **Modular Brick Size:** Standard *modular brick* size is **3-5/8" x 2-1/4" x 7-5/8"** (Width x Height x Length). When including a 3/8" mortar joint: - **Nominal dimensions:** 4" x 2-2/3" x 8" But let's use the actual brick size plus the joint for accuracy. --- #### **Width Calculation (6-1/2 bricks wide):** - Each brick (lengthwise) = 7-5/8" - Each mortar joint = 3/8" For 6-1/2 bricks, there are **6 full mortar joints** between bricks. So, - **Total width = (6.5 × brick length) + (6 × mortar joint thickness)** - **Total width = (6.5 × 7-5/8") + (6 × 3/8")** - **Total width = (6.5 × 7.625") + (6 × 0.375")** - **Total width = 49.5625" + 2.25"** - **Total width = 51.8125"** --- #### **Height Calculation (29 courses high):** - Each brick (height) = 2-1/4" - Each mortar joint = 3/8" For 29 courses, there are **28 mortar joints** between bricks. - **Total height = (29 × brick height) + (28 × mortar joint thickness)** - **Total height = (29 × 2.25") + (28 × 0.375")** - **Total height = 65.25" + 10.5"** - **Total height = 75.75"** --- ### **Final Answer:** **The inside dimensions of the window opening are:** - **Width:** 51-13/16" (or 51.8125") - **Height:** 75-3/4" (or 75.75") Let me know if you need these in feet and inches!